Nice one!
The Spanish Pistol Proof Date Code will also tell you when it was Proofed/Mfg'd
Star Firearms: Dating your Star Pistol with Proofmarks
Lots of these Model B Stars have added on German Waffenamt (sp?) marks put there by importers to raise their value. A lot of the Bulgarian surplused Mod B pistols brought in in the 90's were done up with the fake markings.
There are published ser# ranges for the German Nazi contract Star Mod B pistols so they can be easily ID'd.
3 Magazines is a good extra deal.
If you are buying any more, make sure they are the 'narrow base' style also called Early Style magazines.
Later production (50's and forward ) the mag base changed to a wide base that over lapped the butt of the pistol and they will not fit the early style frames.
mags for the Model A (9mm Largo cal) and Model B (9mm Luger cal) are the same except for the feed lip length.
The 9mmLargo mags feed lips are just a bit shorter in length than the 9mmLuger mags.
But usually they work in either cal pistol.
Both mags will interchange in the Models A&B.
The early style narrow base mags will also fit the still earlier Star Model 1922 pistol (9mm Largo).
That pistol later became the Model A pistol.
The 1922 mags didn't use the folded over lips on the mag base.
A pinned in place mag base on the 1922. But the narrow base Model A (& Mod B) mag with their style of base retention will work just the same.
They all used to be inexpensive,,not anymore.