since it is a didicated Pac, wasn't it cheaper to get the first one ? $15-$25 comparing to the second and still need to splice the wire (more work). Plus on top of that, you need to cut a hole in the cabinet for the second power supply.
Anyway, the second (new) Ps has a built in FUSE. AS far as the RC filter, I dunno where it would be in the original. Isn't it built into the INTERLOCK in the original ?