I thought it would be a piece-of-cake to remove the little tab from the front of the TC. John Shaw said that he removed the front ring plate to more easily file down the tab. So I decided to do just that. I found out that the circular spring and three especially shaped shims will fall out if not carefully retained, along with the alignment pin and its handle. After filing down the tab and attempted to replace everything, I realized that all the aforementioned doohickies had fallen out. With about a half hour's fiddling I seemingly got it back together, and it appears to be OK. Is there any place where I can find the proper sequence and orientation for those rings? Incidently, how many people have noticed the identification label(?) visible on the glass if you look at it in reflected light and leave the rear cap on? It says: LF-1 MADE IN JAPAN. Wonder?