I was hoping the 05 in casting didn't designate MC 05. (was going to sell if it was) I think MC07 is good news?
https://www.marlincrawler.com/docs/mc07/index.htmedit: Had another look and it sure looks like pic of MC05. I'm going by contour of forward flange lower right of adapter where "marlin A A crawler letters are cast in?
Where would I look for a serial#?