Walt Disney's "Once Upon a Wintertime", #D12, 1948,1950. Good condition. There is an "A" on the last page. The price is 35 cents.
"Dale Evans and the Coyote", #253, 1956. Fair condition. There is no letter on the last page, but on the first page it says "This is a brand-new book, written and illustrated especially for Golden Books". The price 25 cents.
D12 sold for 25 cents in the US and has a book value for a mint copy of 20.00. I believe the book sold for 35 in Canada but do not know their values. #253 has to have an edtion on it. Did you look under the spine on the back page? Sometimes it is covered by the tight staple.
The edition letter (A,B,C,D,etc) doesn't change the value really in today's collections. Even though everyone wants an A, they are sometimes hard to find. You should get around the same price listed for the above quote. But, only expect that much if your book is like new. The economy has really discounted LGBs values, along with many other vintage collector books. If you have a lot of books, it's best to at least invest in a Field Guide of LGBs. It gives a roundabout price for books. You just have to remember the values have gone down from the prices listed.