Thanks all for the replies. Very helpful.
Skullcap, yes and I will, but I was hoping someone would say "Oh yeah, I remember those, it's a....."
Yes, the stock is an older one. The usual "Hawken" locks are larger. A Chambers Mountain caplock and similar L&R cover the whole inlet and could be fitted. A Chambers late Ketland could be fitted too. Hmmm.....
Bob, Roger and UT, thanks for the tip on the Hawken Shop. I will follow up.
Thanks again everyone.