The Harmony Sovereigns were extremely under-rated guitars. I own one from 1963 that is extremely precious.

If your is a 1260 model (look inside the soundhole) it was the top of the line model built in Chicago out of all solid woods, spruce top with mahogany back and sides. These were not X-braced, but ladder braced and had tons of volume coming out of the oversized lower bout.

These guitars solid for about $85 new.

Many do need neck resets and the action on the fat nexk can be somewhat cumbersome, but vintage affecionados know these guitars had fabulous sound and overall playability, quite unlike most everything else Harmony produced.

Depending on condition which sounds like it has some pick wear and who knows what kind of belt buckle marks, I would put this on ebay with an initial reserve of $400-450. Good ones can bring about $600 and superb ones somewhat more.

There are players who want these. Selling it to a store means they have to pay something on it to allow for some profit upon resale.