RJjenner only seems to work on really old Rugers. Mines not pre war. I’m just wondering if the base action is a good candidate for building upon.
The Pre War that the website is referring to is a style, not an age for M-77's.
They are modified to look like pre-WW2 sporters from the English and Continental makers
https://www.all4shooters.com/en/shooting/rifles/ruger-m77-rifle-50-years/