Let me ask if you have an FFL license?
Not many shops can survive on just their black powder business even on their best days.
Most shops take in all kinds of guns on consignment or trade in's for the purpose of helping folks to trade up to more expensive and more desirable guns.
But without an FFL, then doing some horse trading involving the transfer of centerfire guns becomes more difficult if not impossible.
So do you take in trades, consignments and deal with centerfire guns too? Do you plan too?
Being located in what looks to be a small town area especially, any new gun shop would need to diversify just to survive in these days of internet competition. Have you considered getting involved in the pawn or consignment business in any limited way i.e. - coins, gold, electronics, cameras or used guns to help supplement the BP business to help it survive in the long term?