Funny you should ask. Installing similar latches in the oil door of
Steve Smith's RV-8 cowling is my task for tonight and tomorrow.

Actually, the hard part of the task is taking the floppy M&W door
blank and adding foam core and an inner skin to make it a nice stiff
sandwich structure. Doing that so as to retain some footprint for the
hinge and latch will take a bit of sculpting.

But, anyhow, finding the latches was a chore. Steve called around and
found them at Beech and Cessna dealers for like $60 and $90 each. He
eventually found B&B (cited below) who had multiple sizes for $5 each.
He bought a bunch of them. That was only a couple days ago.

The B&B latches are real Camlocs, and are of a simpler mechanism than
those in your photos. I'll get a photo of one this evening and put it
up on the Web site tomorrow:

www.hpaircraft.com/hp-24

Thanks, Bob K.