Were stocks being made at RSAF Enfield in the 60s and 70s(?) when the ENVOYs were produced?

From what I've seen of the PH, Churchill etc. sporters the wood is usually marked SILE, at least on the butts; would have to go and look at some forends to see about those.

That tends to suggest that either SILE was just the cheapest (quite possible in the 50s and 60s) or no one was set up to make stocks in the UKicon at that time?

If Colin Moon was involved in at least later ENVOY and L42 stocks, I suppose that also supports the theory that by that point at least, there was no one else?