Saw these on Ebay & they appear to be the early rubberized type E buttplates.  Anybody got info to confirm or deny this?  I bought one under the possibility it might be since I've been looking for one for awhile now.  Thanks for the input.

https://www.ebay.com/itm/Colt-A-1-S-P-1-Buttplate-Vietnam-Era-USGI-Issue/112717705467?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

If the link does not work, just punch in item # 112717705467

Link does not work.  The auction was probably suspended by eBay since they are SO ANTI-GUN.

I found the auction and it wouldn't link for me either.

Let's try it this way.

Seems to work.

I have an early 1972 AR15 Sporter which came with a rubber buttplate with an opening for the buttstock trapdoor.   They seem to be rather fragile that's probably why the US military went to the hard plastic ones.   I have never seen a rubber one in my 30 years of military service.  Probably one of the good ideas they quickly failed.  And Colt being Colt never throws away good parts and probably used them on the AR15 Sporters to consume the inventory.

--fjruple