KH Laser Ghia horn problems

[LaserPete]

My 92 KH Laser Ghia horn started sounding at random times, e.g. 4am in the morning. Disassembly of the horn pad shows the horn pad consists of 2 copper plates separated by a thin layer of foam rubber, foam rubber has decayed and there are now multiple electrical shorts between the copper plates. (I've tried insulating some of the shorts, but the problem returns somewhere else within a short time - now most of the foam rubber is just crumbling away).

Has anyone experienced a similar problem? Any advice on the best fix. I'm guessing I can find a replacement horn pad at a wrecker, but it will probably get the same problem due to age.

The KH Ghia had a different steering wheel (2-spoke) to all the other KH models (3-spoke). Does anybody know if the 3 spoke steering wheel had the same horn pad design? If the 3-spoke wheel had a better horn pad design, I could replace the whole steering wheel perhaps?