Those old king/queen seats are virtually impossible to identify. Lots of companies made them, andin the end it really doesn't matter. Even if you could determine it was by a well know, still existing company like Corbin it wouldn't make it any more desirable or valuable. Those seats, while very comfortable just don't have any value. Most people who decide they don't want them just end up giving or throwing them away.
Similarly I don't think the bags have any particular value regardless of who made them. When I sold my '77 GL last year the buyer promptly removed the Bates bags/trunk, Vetter, and freshly recovered K/Q seat then sold the bike for $1,100 more than he paid me (although he had a couple hundred bucks invested in the replacement stock seat). He offered to give me the whole setup back for free if I would just come pick it up.
