The 48s, any dash or barrel length, are in demand. Most of them I see have an asking price around $1000 which seems high but they don't last long when available. The local Cabelas had four of them, different barrel lengths, last February all priced at $999. I bought the oldest one and the other three were gone shortly thereafter. The correct grips are readily available (eBay) (non diamond magnas for under $50) or targets for $100ish. No reason not to leave it just as your Dad had it though, if it was mine that's what I would do. Nice gun, enjoy.
Jeff
SWCA #1457