OK, here is what I did. I'll admit it's not perfect, but it seemed like the best of a few bad options.
The missing card was evidently put in the wrong car, partially a problem with us being in the wrong parking lot. Everyone remembered Reed/Witt as throwing a 65. Peaslee/Wiggins either shot a 55, 56 or 57 depending on who I talked to. So I could throw out the week or pick one of those scores. We are going to score it a 56, basically because it was the score in the middle. Hopefully we can all live with that.