fluval 305 impeller temoprary substitute

Today I cleaned the fluval 305 on my 40 gallon. Hadn't cleaned it for several months. Much to my surprise when i took the impeller cover off to clean the impeller, there was no shaft left in the impeller well. Now I know I am getting older but I would swear I put the shaft in when i put it together the last time. My guess is the shaft broke into bits and disintegrated. I usually keep a few shafts on hand as their is no local dealer for parts. I had no 305 shaft though. I did have a replacement shaft for an AQ 110. It is a similar size but because the rubber boot was gone it wouldn't fit in the socket properly.I wrapped aluminum (reflectex) tape around the bottom of the shaft to make a shim and it is working until i get another shaft in the mail. Anyone else ever see something like this happen?