Dustin McAmera

Zenit with I-22 50/3.5, HP5 in ID-11 1+1.

Canon A-1 with the 85/1.8 on a 1.5x converter. FP4 in Aculux.

With my phone; sorry!

The problem is nothing to do with the red window, or you wouldn't see more than one set of numbers, surely? This is ink offsetting from the backing paper onto the emulsion. I've had it with Efke film, a few years ago. I guess either the ink or the emulsion itself wasn't as dry as it should be before the film was rolled up. There was quite a long discussion of the problem in the 127 group at Flickr (here, here, and here). A telling clue was that the number you would see in frame 3 wasn't a 3; so not from the red window.

Fomapan 400 in my FED Mikron, and done in Rodinal.

Pano by running 35mm film through my Certo Super Sport Dolly. Adox CHS100 in Rodinal.

Canon A-1 with the 85/1.8; Adox CHS100 developed with Aculux.

I have a dead LTL3 and I had a go at driving the pin out of the hinge. You have to do that from the bottom. I used my thinnest screwdriver. It didn't take much force; a few knocks with the handle of another screwdriver as mini-hammer. The top of the pin is keyed to grip the inside of the hinge. However, it only moves 2 or 3 mm before the top housing stops the pin, so you need to get the top off the camera, I think. Worth measuring some dimensions of the two doors to be confident they're exchangeable before you go to much effort, but to get one working camera from two broken ones is a great reward. Good luck!

But why would a leak show as regular streaks? To me that looks like 'surge marks' from the developer. I got a similar effect one time, when I was trying out a 1940's Agfa film. Only, my frames showed one pale streak per perforation; yours seems to have two. I was advised (on Flickr) that I was probably agitating the tank too violently. I can't pretend that I understand completely what's supposed to go on. The guy argued that fresh developer 'squirts' through the perforations, so the adjacent area gets too much development. Anyhow, I tried to be more gentle, and the problem went away. Here's an example of mine:

Agfa Billy Zero with Efke R100, developed in Rodinal.

Adox CHS25 in my Balda Jubilette.

Duo-Ensign 2¼B.

Adox CHS100 in my Balda Jubilette, and developed in HC110.

Try this place: Paulista Foto – Laboratório Fotográfico Profissional Avenida Angélica, 2057 I know nothing about them, but their website seems more or less current, and says they offer E6 processing.

For even more answers, here's an old thread with the same question! Equipment recommendation to process at home

Pinhole camera, Fuji Pro 160C.

127 Efke R100 in my Kochmann Korelle 3x4cm.

Le Tour (on my phone I'm afraid).

Efke R100 in my Foth Derby 3x4cm, and developed in Rodinal.

Pliobond rubber solution is widely recommended, at least for real leather and leatherette coverings. You can get it at Micro-tools (.com or .de in Europe; I am not connected to either except as an occasional customer). I have used it and it works well. Like the rubber solution in puncture kits, you spread it on and let it all but dry before putting the covering in place. The only concern is if the solvent might attack a synthetic covering. I have also used double-sided tape for this job. Not the stuff you might get as stationery; you can get tape with stronger glue than that.

Maocolor UCN200 in my Yashica 44LM.

If you look at the No. 3 (no 'A') FPK at 'Early Photography' (No. 3 FPK - Antique and Vintage Cameras) all three pictured examples seem to have a dimple in the leather on the right side, in line with the top of the folding bed (the photographer's right, if the camera is held with the handle at the top). If your camera also has that dimple, I bet you press that to unfold the camera.

What the OP has is a 44A; it doesn't say 'A' anywhere, but that's what the model is. This is the only one of the three Yashica 44 cameras where you have to use the red window for all 12 pictures: see the three Yashica 44s at Camera-wiki. The original 44 has a reciprocating film-advance lever, which will wind until you have advanced one frame, then lock up until you expose. The 44LM has a winding knob, which again locks when you have wound far enough. I have my 44LM here. Like Murray's camera, the red window is in the middle. You only use it at the start of the roll; you wind until you get the number '1' in the window, then you slide the cover over the window, and press the little knob on the side that resets the frame counter. So yes, you use the 'Frame 1' marking of the 1-8 numbers. At the other end of the film, when you have exposed number 12, the camera will wind as much as you like, since you're now taking up all the tail of backing paper.

I'm using Firefox 55.0.2 (just updated). The site info shows photo.net as a secure connection, with a certificate by Digicert Inc, expiring in October 2018.

You could try deleting all your photo.net cookies; just a guess.