I was able to get the nuts off of mine pretty easily last weekend.
Some careful pressure on the base at different angles and a hand held nut-driver (11/32 I think) and I was able to get them right off.
Looks like the original nuts were chrome plated brass. Probably why they were so easy to come off after 40 years. Had they been changed to stainless at some point, I bet it wouldn't have been so easy.

Sea Dog used to make replacements, but looks like they stopped producing them. I picked up a couple of new old stock off of ebay for about 8 bucks.
Heres the old Sea Dog part number:

Windshield Loop Latch 324220

https://i.ebayimg.com/images/g/hA8AA...7aT/s-l500.jpg

I bought a set off Ebay today. Thanks for the lead!!!! You guys Rock!

Folks: They claim they have 35 more latches in stock. Get them while they last.....

Thanks. I found them!!! Will try your method later today. So, I know this is fine detail but my issue with these on at least my boat is that the legs on the loop hatch are short and thus, don’t engage the frame to lock. These seadog ones have short legs as well. Now that the hole is where it is I’m not sure that even a replacement will engage the opposite frame to lock. I’ll maybe have to start in a new place and bring it further out? I’m sure someone else will run into this if they haven’t already. Regardless, these are a major PITA.

Sounds like your frames may have loosened up - check that first.
If everything is still tight and the new latches don't fit then measure how big they would need to be and I can modify the file to those dimensions - then you can print custom ones. Buying NOS off Ebay is definitely the best answer if they work.

Also - you may be able to carefully cut the nuts off with a dremel or break/split them with a small nut breaker/splitter

Bought a set this morning. Thanks for the info, John!

Don't thank me, thank Zachary! (Erebus)

I have a plastic bag full of them that came off the multiple winshields I have picked up. When I put mine back in there was no reason for ever opening them again so I bolted them shut with brass machine screws and nuts. never use stainless on aluminum.

So I got the three that were bothering me off! My window is tight. powder coated it not to long ago so I’m guessimg they put it back on right.

No problem, just did the needle nose technique. I ordered the seadog ones, Thanks Zack. Does anyone know if they are the exact same size? One of my pegs is mis-firing bc they started to far off Center. Not sure why? I’m not sure that the new one will even help me any or not. I’m not sure I can move that peg over any without taking off the windshield unless someone has a better idea. Thanks again

Bumping this old thread b/c I was searching for these Windshield Loop Latch replacements:
Looks like I just missed an eBay auction for a pair of the Sea Dog 324220-1.

Then I found and ordered two pairs of these, Diversified Products 480-750B:
https://pinelakeparts.com/products/4...gn=sag_organic

Related subject, I've matched the original locking knob to these identical replacements:
https://www.mcmaster.com/6479K55/

I'll be matching up replacement nuts and nylon shim washers also before ordering from McMaster-Carr.