I recently "inherited" a Craftsman 500 router shortly after my
nearly 30-year-old Craftsman router became unusable. I went to Sears
and purchased a "guide kit" for the 500 but to my great surprise
discovered that there was no micro-adjust of any kind on the edge guide
that comes with that kit. One would have to "tap" the guide to the
desired position making it virtually useless for mortising and
tenoning.

The 500 has no holes in the base for a standard edge guide with two
slide rods that fasten into the base a half inch or so from the bottom.
The only way to fasten an edge guide to the 500 is by removing the
plastic sub-base and screwing the edge-guide to the bottom of the base
in place of the normal sub-base.

Is there any edge guide that mounts to the bottom of a router in this
way and also provides some form of continuous adjustment?

Thanks in advance for any help!