Hi (((Echo))),
On the old board, I had a good thread that answered quite a few of your questions. I don't have time to reconstruct it at the moment, but I will do my best to summarize.
The M54-1's that come from Lever appear to be part of a consignment that was origionally intended to be imported by dealers in California, as evidenced by markings on the slide:
Markings on left of slide. Top line reads, "MOD. 54-1 7.62x25", followed by the serial number. The first half of the lower line has been overstruck by 5 columns of 3 lines made by what appears to be a point impact engraving machine, but may have read, "GR(?) L.A. CA". Remainder of lower line reads, "MADE IN CHINA KSI POMONA CA".
To comply with U.S. law they were fitted with a manual safety on the left hand of the slide:
Location of safety and safety markings. Safety has been removed from this example.
The 7.62 barrels are unmarked, but the 9mm ones are marked "9X19MM" over the chamber, visible through the ejection slot of the slide when the slide is in battery.
The Lever arms ones come with (1) 7.62 magazine and (1) 9MM magazine:
Top view of the magazines. 7.62 on the left and 9MM on the right.
Side view of the magazines. 7.62 on the left and 9MM on the right. Notice the presence of a finger rest on the 9MM magazine, a feature that greatly enhances the handling and pointablility of the pistol, in my opinion.
Overall finish of the M54-1 is rough, but in keeping with the price.
The M54 available from Marstar is essentially the same, with the exception that it does not have the unsightly safety, and the slide markings are substantially different. They also appear to be marginally better finished. Barrel markings are the same, but I have not seen a 9MM magazine from Marstar.
Reliability with 124gr 9MM and 7.62x25MM Czech surplus is excellent in pistols from both dealers. FTE's can happen with 115gr 9MM with a weak grip.
Accuracy leaves something to be desired. Sight visibility is greatly improved with some red or flourescent paint.
Trigger is rough and spongy out of the box. It improves a lot with wearing in, but it's design will likely defeat attempts to make it truly "crisp".
Whether you go with Lever or Marstar - or someone else entirely - remember that what you are buying is a full power military pistol for under $150. That should tell you something. The accuracy, fit, and finish are not going to match a $1000 "name" brand gun. So don't expect it. Too many of the people that I hear #####ing about the quality of these guns have expectations wholly out of line with the price tag. For what they are, these are great little pistols, good enough for punching paper with cheap surplus ammo.