Armas Bost (founded by Jose Bolumburu; maker’s mark ‘JB’) was a shotgun maker in the traditional Spanish manner; it made shotguns to whatever price point a customer could afford. The vast majority of Bost guns encountered here in the US are low cost ‘working man’s’ guns purchased from Bost by hardware stores and the like to be sold to hunters with limited budgets.
Low cost does not mean low quality; it means little engraving and what engraving there is will be simple. Under whatever engraving it may have is a solid, well-built gun that with reasonable care will be handed down through the generations.
In terms of when your gun was made, check the proof marks on the barrel flats. Up until 1995 the Eibar Proof House used a year code to indicate the year in which a gun was proofed. Here is a list of those proof year codes:
http://personales.jet.es/rafa/b_punzones_eibar_fecha.htmlHere is a marked up photo showing the barrel flats and manufacturing marks:
Hope this helps.
