[Amps] 3-500Z socket types

[W2RU - Bud Hippisley]

I have a very early Amp Supply Co. LK-550 which uses three 3-500Zs.  I have had recurring problems with getting all three bottles to "light up" when I power up.  The problem appears to be excessive resistance at the junction of the filament pins and tube sockets.  The ceramic sockets in this rig have a removable spring clip at each of the five tube pins, and I have re-bent some of these for temporary relief.  But getting underneath the aluminum platform the tube sockets are mounted on is a real hassle, and I risk damaging the plate choke each time I do it.

Is there a different type of socket for the 3-500Z that I could install?  Otherwise, my next step may be to solder the tube filament pins directly to the filament choke leads....:-)

Tnx & 73 -- Bud, W2RU