So this one may take a little more work, but the idea is great! These are just stamps people have collected and mix n’matched to their liking for invitation postage. The stamp will have the same face value as printed back in the day, hence the amount on one card, but you need to make sure the stamps are unused before purchasing. Ebay , Champion Stamp and Kenmore Stamp Co. would be 3 great places to start looking!
Key words: face value vintage stamps