Virgil I. Grissom valuation?

pheh

About 10 years ago I bought a small collection of astronaut signatures. The centerpiece of the collection was a NASA envelope postmarked July 21, 1961 (date of the Mercury-Redstone 4 launch and subsequent loss) with his signature on the envelope. If authentic - could anyone hazard a guess as to its value?

TIA.

PipestonePete

Can you post a scan of the envelope?

ColinCMR

i have Marc Garneau's (1st canadian in space) auto in black on a black/white poster card, any idea on what it may be worth is welcomed