Thanks, tlin! I'm glad to see the ol' gal still has some followers. I appreciate the encouragement. She's coming along nicely. Lots of time consuming details at this point in the game, but we're getting there. Hopefully I'll have some good progress pictures to slap together soon.
You may be sorry insulating and sealing that floor unless you will store the trailer in a garage. If stored outside, that insulation will draw moisture and vermin will be living in the insulation in a couple of years. Not much heat is lost through the floor so that much insulation is uneccessary.