Custom Gibson Mutant RB-250 banjo 1954 Sunburst

The legend I got from the previous owner is the original owner hated the bowtie inlays, and Gibson wouldn't make him a replacement neck, so he had one made. Myself, my first thought was it's a conversion, but here you go. What it is (and please keep in mind that banjo's, to me, are an arcane lore, one I am woefully ignorant of) is an original 1954 Pot (going by the 4-XXXX serial on the inside), tone ring, rims, etc- everything but the neck. Has Gibson Machine heads, the patina matches so would like to think they are the original that would have come on the original neck. Doesn't look like anything has been replaced, except possibly the armrest, and I say that because it's chrome and not nickle. The neck looks good, plays fine, but the finish isn't on a par with Gibson's. The neck appears to have a guitar truss rod cover, I kept thinking I had a banjo cover, if I can find it I will swap it out, but that's up in the air. Enjoy the pictures, any questions or observations feel free to share. We're off gigging every weekend, so if you don't get an immediate response, my apologies. I think this would be a killer instrument with a Gibson neck, it's pretty durn cool as it is and sounds great, lots of snap. Thanks for looking!