Jim, About the same time that you were looking for a 1965-66 upper and lower cowl, we were too. We thought that we had found one through Summit I think. The sale went through and a day later we got e-mail notification that it was out of stock at their "drop ship" supplier. I assume that would be Dynacorn.
Mid week this week, we found one source online that has them again. The Dynacorn WTP 2012 version. It was at CJ's. We ordered it and it should be dropped off at my/our Shop today Saturday 11-20-21. I hope it survived the trip because if it is bent, it is going back. I guess Dynacorn got one of their containers that was held up in shipping.
By the way, earlier this week I laid the cut off '65 cowl panel on top of a '66 and finally see the difference in them. I haven't found anyone making early 1965 wiper arms with the threaded shafts to use on a '66 if one uses the replacement cowl upper. Greg