Frosty, I'd pass it by - -
I mean, if you figure this particular item has collector value, fine. If you have some insight into the design and have experience in making them run, excellent! But I'd feel remiss if I didn't pass along my history with this particular type.
I didn't like the M61 Escort- - - - - And I really, REALLY, wanted to like it.
When it first came out, I thought it would make an excellent training piece for my then-wife's Beretta 418 - - Near about the same size and grip angle. Cheap, .22 LP practice with a pocket pistol!
A friend, gunsmith, inveterate pistol tinkerer, had one, like new, with an extra magazine. He advised me to NOT get it. I insisted. He said, here, take it and try it out - - You won't like it. Nope, I was bull headed, and I ended up trading a collector grade Nambu serrvice pistol , with accessories, for the M61.
Sometimes this M61 would go through two magazines without a malfunction, sometimes not. Tried about five different types of ammo, HP and solids. Worked best with Remington High Velocity solids, but I still couldn't get it to run for 20 rounds without a problem. I cleaned it, I oiled it, I cleaned it again, I greased the slide/frame interface.
This was the only "backup gun" for which I thought I needed a backup. Finally just cut out the middle-gun . . . .
I ended up selling it the same way I bought it - - To a friend, whom I gave clear and detailed warnings about the problems. Yes, any design can have a lemon occasionally. I knew two other guys who had exactly the same kind of problems. And heard second hand of a few others. S&W finally discontinued the little gun - - It was fine as a .25 ACP, but NOT as .22 LR.
Sorry to be a doomcryer, but I'd not want to think of you relying on an M61 for personal defense.
Best regards,
Johnny