Thanks Stuball, do you know what model Guild is marketing today that is similar to my D40?
Welcome aboard Eddie.
I think you meant "F40" as in your original post and Guild does not actually offer (what I consider to be) a "true" F40 at this time.
Your F40's (and all F40's until now) defining characteristic was a
16" wide lower bout jumbo shape.
The body woods and construction had many variations over the years but that was always a constant.
I've been a bit vocal about my displeasure that Guild has seen fit to put the F40 name on a
17" lower bout jumbo body,, they even acknowledge that originally that was known as an F4
8 because it was actually in the F50 family which had only had a maple body and a rosewood body up until the 'hog-bodied F48 was introduced.
You're not going to find a true replacement value for a true F40 except by averaging selling prices from on-line sales and/or actually getting it appraised.
Agree with Stuball though, $1200's probably in the ball park for one of those and maybe higher depending on condition and due to the fact it's actually not available new anymore, or "at this time", at least.
Closest you might come to "new" is a late (2014) New Hartford F40, but those were actually mahogany-bodied.
(Just realized you may be unaware that Guild had several factory relocations and even a new ownership over the last 15 years. New Hartford CN was the last production site before the move to the current factory in Oxnard CA)