Re: fn 1905 pocket pistol
Those are almost identical to the Colt Vest Pocket model that collectors call the Model 1908, and many parts of the earlier guns will interchange. Both guns are highly reliable, but the lack of a manual safety may make it less desireable for carry.
As noted, it is the first variant, without the thumb safety. The second variant has a safety combined with a slide stop, but in a different (and IMHO, better) arrangement than in the Colt. Well over a million of those guns were made and sold all over the world, except in the U.S., which is why they are uncommon here. That was due to an agreement between FN and Colt, by which they divided up the market - Colt got the Western Hemisphere, FN got Europe and the Middle East. The Far East was up for grabs. The result was that FN Browning pistols were not sold in the U.S. until well after WWII, when the agreement ended.
That pistol looks to be not only polished down but plated (chrome or nickel) as well. $150 seems about right.