Hi Aaron,
A M1929 Bern with serial # 71130, according to the V. Bobba book info. should more than likely have the later black plastic grips and magazine. Brown switched to black plastic in the Ordnance lugers around # 65xxx. Even with a couple of hundred guns overlapping, # 71130 seem a little late to have brown plastic, IMHO.
The firm price seems a bit high. I would hope to pick up such a # 71xxx gun in that condition for around $ 1800 or so from a fellow collector...a bit more from a retail dealer with retail shop overheads.
The folks at FGS are selling this one with holster for $ 1750 (see bottom of page) :
http://www.fgsinc.8m.com/catalog.html
(This one is an even later # 73xxx also with brown plastic).
Simspons has a few late Berns in the $ 1900 to $ 2200 price range in strong 96% + condition.
http://www.simpsonltd.com/index.php?...sort=2a&page=2