From pasadenahotrod on the HAMB.
When I started in the old car hobby and then the business, the most desireable rear Model A rear spring was the A-5560-C low crown 7-leaf spring used under 28-31 Roadsters. Originals with original clamps have AC stamped in one of the clamps. An easy $75-100 any time you found one on a junk chassis or rearend or in a pile at a swap meet, and no end of customers. Now nobody even knows what I'm talking about.
Some other Model A spring stuff:
Tudor rear springs differ from all other because they do not have the reverse arch in the main leaf from the top crown to the spring eye. It is a straight line. These are 10-leaf springs with AA stamped into the original clamp.
8-Leaf springs with AB stamped into the spring clamp are found on Phaetons, Coupes, Sport COupe, Cabriolets and Victorias.
10-leaf springs with AD stamped clamp are found under Town, Sedans, Fordors of all styles and Sedan Deliveries.
10-leaf springs with AE stamped clamp are found under Panel Deliveries, Pickups(open and closed) and Station Wagons.
The only difference between the AD and AE springs is the #2 leaf which is .260-.270 thick on the AD spring and .300-.310 on the AE.
