On Mon, 15 Dec 2014 11:14:16 -0600, Chet Kincaid
wrote:

Original panel dates to 1957. No issues with it but I've read about the
many bad things about this unit. Also, the local codes now require 100A
service and the present panel with two mains of 30 for the dryer circuit
and 50 for the rest of the panel is now obsolete.

So the question is whether anyone is offering replacement internal guts for
this unit. It's model 116-68C. If so I think I'd go that route.

Old box is flush in the wall.

If an entirely new box is needed, could one remove the existing guts and
leave the old box in place? Mount a new panel right inside the old and
maybe use the old cover, cut a big rectangle out leaving just a sort of
rectangular ring and place it so as to cover the area where wires are
emerging from their conduits (formerly the interor of the old box) and
going an inch or so to enter the new box.

OR

What if one got a new box that was intentially larger than the old and
mounted it on the surface in front of the old box? Again, the old box
would be stripped of guts, and the cover removed and the box left in the
wall. Wires could enter the new box from the rear. Those existing wires
able to reach a breaker could go directly in. Those too short would just
have new, longer runs pulled from their first place they go to (outlet box
typically).

I have a FPE Stab Lock panel in my house from 1979. It has a 100A main.
I've never had any problems with it. I also considered replacing it,
but I was told by a local electrician that they were improved in the
70's and a 1979 panel is as safe as any other breaker panel. While
everyone has their opinions, I am not sure what to believe.....

However, in your case that is a really old panel, and with the main's
problems, I'd be more inclined to change it.

I'm sure the guts of any panel can be modified to fit the panel, as long
as it is not too large, but you'll have to modify the cover door too, so
the breakers fit. That seems like a lot more trouble than just changing
the whole box. Either way, you'll have to pull the meter. If you have
to cut away a little plaster, why not just fill it in with some sort of
decorative molding.