When I purchased my M35A2 (back before GL days) at Ft McCoy auction, it did not have a ring mount. But it did have spent 50 Cal brass and some loose links under the seats.
The hood has an extra Latch on the right front that looks like it was a field modification. Salvaged from a Can Point Vehicle. When I had a ring mount on it it required a small fabricated angle bracket on the front leg that matched the extra hood latch. Worked great. I left the extra latch on the hood just to see if any sharp eyed vets notice.
A couple of GI's have stopped and looked at it and said 'Oh, it had a ring mount at some time". Very matter of fact.
Just another form of yankee GI inginuity.
Cat Man