The LEEWARD is a 16' model similar to an O'DAY Day Sailer I (well, sort of?).
I think the Southwind and Windward are basically the same boat, the difference is mainly that the SOUTHWIND has a retractable keel that is totally below the hull, and the WINDWARD is a CENTERBOARD design with the CB housed inside the hull. (Windward is an older version of hte Southwind) I have an old (1981 and 1982) catalog, but there used to be a LUGER BOATS website mantained by a few owners. "The Luger Mooring".... unfortunately it seems to have disappeared!
I'd suggest "googling" LUGER, see what you find...... I think I found more info on a couple of general sailing sites, like one on trailersailing. Try the Small Craft Advisor Web Site (and magazine).
I can try to answer questions based on my brochures.....
PS: the "SOUTHWIND 21" is really only 20' long........ Luger got 21' by measuring around the curve of the gunwale! Pretty sneaky!!
I'd say 2 people could cruise in relative comfort on a boat this size, it will be a couple of steps above sleeping in a tent, and many couples have happily cruised in smaller boats. However, a lot depends on how the original owner built/finished the boat, these LUGER boats were all "kit boats" and were completed from bare hulls/decks by their owners.