"Hey, I have a envelope flown on the first flight on the B-19 too! What is it worth?!"
Every couple of months, we at Check-Six.com receive an e-mail or phone call from someone who has found one or two of these covers in a framed display that has been passed down in the family for decades, stowed away in the "war chest" of a deceased loved one, or simply dumb-lucked into them at a garage sale. Many times, the e-mails have the feel of an "Antiques Roadshow" where the person on the other end of the e-mail envisions the vast wealth that we be theirs upon the sale of the envelope, and merely await our confirmation (and requisite low-ball purchase offer) of this perceived "fact".
And the truth is, these covers are indeed a piece of history... However, they are a relatively common piece of history.
There were over 75,000 of the covers flown on the first flight of the Douglas B-19, and was a part of the largest single special airmail cargo of the time. These covers regularly list on eBay, other websites, and sales venues for under $20.00 - in excellent condition. As with most things, poorer condition (tears, water spots, and wrinkling) further drives the price downwards.
The suggestion we make to those who possess these is to hold on to it as an heirloom of importance to the family ("This belonged to Grandpa") and not part with it for monetary gain. However, if you are insisting on parting with it, we can facilitate, but urge you strongly not to quit your job or plan a European vacation based solely on the sale of this item.
The Crew at Check-Six