The little cylindrical spacers that separate the horn ring from the attachment plate have a height of about 3/16", under a wider washer-type top. The holes that they go through on the attachment plate are 5/16 diameter. My spacers were crushed or swolen to the point that they were frozen into the attachment plate holes. Without free movement of the attachment plate on those spacers, the horn ring could not be properly installed with all three tabs engaged, and the horn was hard to get to make contact. Original replacements for those spacers are not available.
On the advice of fordor41, I ordered an assortment of black nylon spacers and washers from Amazon:
https://www.amazon.com/dp/B0CBBC9SR1?tag=atomicindus08-20
That $5.00 set includes 30 pieces which are 7mm in diameter (fits nicely in the 5/16" hole), 5mm high (just a shade over 3/16"), and has a 4mm diameter hole that nicely accommodates the 1/8" diameter screw. The set also comes with thin nylon washers of 9mm diameter, which is big enough to cap the 5/16 hole in the attachment plate.
I cleaned the light corrosion off of the attachment plate and the inside of the horn ring to ensure good electrical contact. The foam ring you can buy anywhere. It acts like a firm spring, and works fine.
I put it all together and with a strong push-and-turn got all three tabs to engage, without breaking those famously breakable spokes on the '41 horn ring. The horn ring now sits level and works properly.
I think that all horn rings from '41 through '48 attach the same, so this fix might work for any of you having trouble with improper horn ring function.
