
The model B pistol is the 9 mm Parabellum/Luger variant of the A/B series of 1911-inspired pistols that led Star design for the next 60 years. The models A, B, P and M had roughly comparable upates over the years.
The various types of Model B pistols, while still in the same family, have enough variation that three different stripping procedures are needed. Luckily, I now have all three to give in one format or another.
Manufactured starting in 1924, and really just a minor variant of the model A. This pistol resembled the earlier guns, with a small safety lever and straight backstrap. Only a few seem to have been made, probably all for export sales. Note that none of the images on this page depict this pistol, as I have never seen one. It would be fairly rare now, but should be clearly marked, so is easily identifable.
In 1931, production shifted entirely to this updated version which added several, mostly external,features to make the pistol look and handle more like the Colt 1911A1. The frame was changed to provide an arched backstrap and a larger safety as well as more rugged and higher-visibility sights were fitted.
Large numbers of these guns were produced. The image above is a typical european commercial model with wood stocks and blue finish. Many variations of finish, stocks and sights were produced. This basic model B remained in production continuously until 1983.

During the Second World War, Germany issued a number of small arms not internally developed in order to fill gaps in production. An especially large variety of pistols were issued, and among these were a relatively small number of "B .08" pistols. These were issued to German Police and "certain military units." In general, lower-priority organizations such as the police could not get first line German-made weapons during the war, so external contracts such as this are not unusual.
These were made for only from 1942 to '44 and are substantially Second Model B pistols. The only changes of which I am aware are to markings. Reportedly, Stars issued to WWII German troops do not carry Nazi proofmarks, the only foreign arms exempted from this requirement. But, I have encountered some owners with overtly german proofed weapons, so this may be untrue, or inconsistently applied.
All these pistols should have the last 3 digits of the serial number on all major component. Note that marks along the lines of "P'08" on the chamber hood or "F. Patr. 08" are just ways to denote 9 mm Parabellum, and do not mean it was necessarily German issue. For extra confirmation, check the date of proofing. they will most likely display date codes N, Ñ or O. Positive identification of these pistols, to me, still seems difficult.
Made from 1946 to the end of classic-model production in 1983, model Bs with Super upgrades were produced. The major change is the replacement of the swinging link with a Sig 210 (or modern Star) style closed cam path integral to the barrel. Related to this, a full-length guide rod with captive spring, and a quick takedown lever were added as well. All of these models have a magazine safety, but one slightly different from the later S variants, and the extractor is modified to double as a loaded-chamber indicator. Additionally, the sights are improved in shape to make them easier to see, and minor changes were made to the trigger system.
The BM, BKS and BKM are shortened, compact versions of the basic Model B pistols. None were made in the "Super" configuration with the linkless barrel.
The BM is steel while the BKS and BKM are alloy framed. The BM and BKM have the same dimensions, and are noticably smaller than the slightly earlier BKS (see the comparison diagrams below). The BKS was also sold in the US under the Starlite name. This is presumably because it was unusual at that time to have an alloy frame, so the light weight was of note. The BKS, at least, had a magazine safety as on the BS.
While used model BMs are still relatively cheap and plentiful, the alloy framed pistols are decidedly not. This may indicate that 1970s aluminum technology was not in fact up to speed, and few have survived in a shootable condition.