Karl,
Welcome to the Model 52s. I lucked into 52 no dash, a few years ago. Some dope had used some kind of goop to build up the trigger (too cheap to buy a trigger shoe?) so the price was right. My gunsmith was able to remove the mess and now it shoots great. The original 52's had essentially the same trigger mechanism as the Model 39, with a set screw to lock out the double action feature. The -1, and -2's have single action only triggers.

For loads I found 3.0 grains of Bullseye works just fine. I usually use Berry's or Rainier 148gr plated DEWCs. I've have good results with True Blue as well. As I noted in another thread, IMR Target is not looking too good. I keep the cases trimmed as the magazine is unforgiving when it comes to COL. A lot of loads listed in the manuals are meant for revolvers and will not cycle the Model 52. I keep trying though. Purchased a case of .38 Special from MCCI on GB not long after getting the pistol. Was pleasantly surprised to find the ammo was all new with Berry's bullets. Perfect for indoor use, and it cycled the 52 without a hitch.

Magazines can be hard to come by. I've been told the 52 was popular for some form of combat shooting competitions and the shooters would modify the mags to hold 6 rounds instead of 5. Could be just a rumor as I have yet to encounter any so modified.

All that said, have a blast with the 52,