As a result of Wallic's calculations,...
As a result of Wallic's calculations, the main bow just barely clears the tack strip and the header bow overhangs the halo bow just enough to not pinch the topping. Note how that side-iron pivot stops just short of the jamb.
As noted before, moving the top forward makes the header bow overshoot the windshield. Complicating matters was the windshield itself; Wallic angled it rearward to make the car look swoopier, thereby exaggerating the amount the top overhung it.
Shortening the Side Irons
To realign the header bow and windshield, Wallic needed to shorten the side irons. The question was which ones? Each side has two elements: a straight leading iron and a doglegged trailing iron, known henceforth as leading and trailing irons. The forward ends of the leading irons indirectly bolt to the header bow and the rearward ends of the trailing irons pivot on the main bow. Naturally, the irons' open ends meet near the middle of each window opening.
The final cut map offers a...
The final cut map offers a concise perspective. Wallic left the leading (straight) side irons alone but trimmed the trailing (doglegged) side irons 2-5/8 inches. Trimming the halo-bow legs 5/8-inch shorter than the trailing side irons (3-1/4 inches total) brought down the halo bow and top crown.
Simplicity suggests shortening the leading irons but Wallic remembered how the pivots overhang the door with the top down. Some eyeballing indicated that the trailing irons dictate the pivots' location, so on a gamble he shortened their front ends until the header bow aligned with the windshield. The bet paid off; just as his eyeball suggested, shortening the trailing side irons made the pivots land just behind the jambs, which makes one wonder why Ford didn't shorten those links and extend the straight ones in the first place.
Flattening the Crown
Clipping the trailing side irons made the top fit the windshield and its pivots land in a better place but it screwed up the geometry for a secondary bow just ahead of the main one. This bow-we'll call it the halo-determines the roof's crown profile. It pivots directly on the trailing side irons but another set of shorter legs link it to holes in the leading side irons. Shortening the trailing side irons moved the halo closer to the leading side irons, but the stock-length links between the leading irons that the halo made the top point up as if it were a tent.
Wallic then draped and taped...
Wallic then draped and taped a garbage sack over the bows and tested the profile. Though good, he deemed it not good enough as the main bow sat just a touch too high for his taste.
Wallic could've just shortened the legs that linked the halo to the leading irons by the amount he shortened the trailing irons, but that presented its own problem: even back in its stock location, the crown looked too high for the lowered top. So Wallic tested crown heights by clamping the halo's links to the side irons at various locations. In the end he left the halo bow and irons intact but shortened the legs that link the halo to the leading side irons by 5/8-inch more than he shortened the trailing irons (the photo really will make sense of it). As a result, the halo bow laid down just a little bit lower, thereby reducing the crown at the middle of the top to match the top's profile.
Conclusion
The three preceding steps outline the biggest modifications that Wallic made to his top but they're far from the only changes he made. In fact, during a trash bag mockup, Wallic concluded that the top would look better if he took a hair of height out of the wood in the main bow. Nor were the changes he made set in stone. Windshield chop and angle, top angle and style, and occupant height ultimately determine a top's shape. These things underscore the importance of making each top fit the car, its style, and its occupants.
We admit it's a fair bit of work even with stock-type irons. But making your own top to suit your needs is work that pays off. Just as you won't pass up a roadster ride even if the weather looks sour, you'll never pass another car with a top exactly like the one you built yourself.
Lowering the entire main bow...
Lowering the entire main bow would taper the window opening to the rear, require trimming more from the side irons, and possibly throw off the top geometry. So he cut a bird's mouth in the main bow's wood and shoved it down. That's the reason he cut the additional 1-1/4 inches from the ends of the bow.
Wallic assembles a lot of...
Wallic assembles a lot of his parts with rivets but they're good for more than just holding things together. In case you haven't noticed, most hinges are riveted. Here's how to do it.
Many universal rivets have...
Many universal rivets have extra-long shanks to fit the widest application range. Choose a rivet that's no less than 1/32-inch smaller than the hole. The rivet shank should protrude beyond the work one and a half times the shank diameter. Account for washers if necessary.
The manufactured head of the...
The manufactured head of the rivet will lay relatively flat so it needs no preparation. The formed head needs someplace to go if it's to lay flush. Wallic countersunk the hole in the iron halfway with a larger drill.
The rivet lays manufactured...
The rivet lays manufactured side down on the anvil followed by the first iron, a washer, and the second iron. Wallic struck the rivet just enough to form the head but enough to lock up the hinge. Steel clamped in a vise will do. Rivets can be pre-heated cherry red to ease the process.
Wallic formed the corner-block...
Wallic formed the corner-block rivets the same basic way as the hinges, only he peened the rivets fully to tighten them.
Here's another trash bag test,...
Here's another trash bag test, only this time with the notched-and-lowered main bow wood. The bare frame may look high and spindly, but the topping material will significantly overhang the side irons.