Canon RF Rear Lens Cap A3

[GregV]

Can anyone enlighten me about the model A3 39mm rear lens cap? It is a black Bakelite plastic cap similar to the Model A cap, but it is 15mm deep vs 9.6mm for the Model A. The cap is marked on the bottom surface "Canon A3 Made in Japan. I have two different types. Both have a serrated edge and one has a smooth area at the open top of about 1mm. Outer diameter is about 44mm. The cap will work on the 25mm lens, but every 25 I have seen has the metal rear cap. Any thoughts?

Thanks,
Greg

 

[kermaier]

I think I've seen that bakelite cap on the 35/1.8.