Yes, the heirloom value is probably worth far more to you than whatever it would bring on the market. I've got a Carter Carburetor specification manual of Dad's that dates back into the 1920's that's over 8 inches thick. I won't part with it in my lifetime!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!