Tom Matthews writes:
The following pictures show my method
for reshoeing a drawer in about ten minutes.

Here is the drawer in need.
As you can see it has about 3/16" belly, enough wear to make it
run poorly. However, it is not worn into the groove holding the bottom.
It is still glued well, and with a Knapp joint it is perfect candidate
for my method which does not require dismantling.

This is my secret weapon for making the job go quickly.
It is just a piece of 1X4 set up for vacuum.

Here is the underside of the 1 x 4.

I set it on the drawer end and use a spacer jig to place it so that
I get a clean edge without removing too much material. When it is
where I want it, a simple twist of the air valve clamps it into place.

A quick run down the straight edge with the router - and the cut is made.

Glue on the new shoe. I choose the material carefully because
I want just a little grain runout to make planing it to final dimension
as easy as possible.

After marking a line, block plane it for an ultra smooth bearing surface.
Clean up the start point with a chisel. (If this were a dovetailed drawer,
I would clean up to the end of the tail.)

Check for fit.
Addendum
Vacuum clamping definitely belongs in every shop that
does any amount of repair work. It is also my favorite way
to hold down finished leaves for rubbing.
Vacuum generators are about fifty bucks but can be made
in an afternoon if you are cash strapped as I often am.
Below is a picture of three generators.
The first is made of wood, it is the first one I built.
The second is all acrylic which I use to
pump dirty strip water upstairs for evaporation.
While the third is factory made.