I have left the WA1185 in the fivemega socket because it is perfectly focused (no shim, sits up in the socket a little), and installed a FM1909 in the Tad socket deep as it will go, and I am trying to focus the thing. I held the sockets next to each other so the filaments line up, and I can see the amount I need to shim / / <--- about that much. I thought I shimmed it pretty close that amount, but the beam against the wall looks like a cat's eye. Pulled the shims and looked again, and beam profile is more round, but not focused. Put all the shims on and more cat's eye. Been trial and erring with different combinations of thinest shim, slowing adding thin shims and checking, for over an hour, and I'm no closer... and I am getting tired from all the concentration. The problem is... I can't tell from checking if I am getting warmer or colder, if I need to lower the filament or raise the filament... I can only see that it is wrong. But I suppose I have learned that if the filament is too low in the reflector, there is a cat's eye or football shape effect to the hotspot against a wall, and if the filament is too high in the reflector, the hotspot is rounder, but blurry. Taking a break.