Talk about doing something the hard way. "It only took five mins with a hacksaw."
Definately use the tricircle guide as a reference point if you want to attempt taking your 140 apart. I hope you have a drill press though, because it uses individual retaining plugs. There is no plate. Like so...
This is the first 140 I ever destroyed with my torch. I got that little bugger glowing red hot and dunked it in ice water to hear it's high pitched squelch.
It helped to ease my frustration with the intro to security pins, but didn't help me find which driver was where. I've actually had success with this process 3 times since then on 140's to pilfer the pins for other locks. Out of 4 differently keyed locks all had 4 security pins. 2 had 3 spools 1 serrated, 2 had 3 spools 1 serrated. In my experience it is common, and it wouldn't suprise me to find out the key biting is why you havn't noticed the other security drivers. Getting back to the heating process, 2 and 1/2 mins is way to long with a propane torch set to high. About 1m 30sec is good at medium heat. Really you have to watch the color to see when it is just about glowing, then dunk it in water. Even this one I cracked getting it red hot had 3 working springs and the pins were fine. It still works with 1 pinstack, although it isn't as smooth as new I have no doubt it could be replugged with the original parts inside and still work well with the key.
You could also use a drill press and a tiny drill bit. Either way please don't cut it in half. It will come apart without the need to use a hacksaw.
It's been awhile, but I think the shackle retaining pin is on the backside Master stamped face. That's if you have the lock unlocked and on the table with shackle swung open to the left, it's on the underside stamped face slightly more than halfway up from the bottom above the r in Master. If you do a video, probably wait until your done to film the results. Proper dissassembly can take some time and patience. You don't want to be rushed through the process. Good luck with it.
-Tooly
