Bob Simon wrote:

My wife has been talking about replacing our front door with something
nicer for several years. We are both strong proponents of recycling
so today when I came across a beautiful old solid oak door with leaded
glass (already stripped) for $75, I got pretty excited.

Unfortunately, the measurements do not exactly match the existing
door. The used door is 1 1/2" shorter

I would add a scab to the bottom edge, then put a brass kick plate on
both sides. No one will notice if you don't point it out.

and 1/8" narrower.

Put some 1/16" shims behind the hinges. The difference will be
unnoticable. Many doors have more than 1/8" slop.

Also, there
are two 2" holes drilled in it. The deadbolt hole is not even close
to where my existing deadbolt is located and it's too big.

Visit a good locksmith. He'll sell you a deadbolt that will use your
old key and fit a 2" hole. Move the strike plate on the jamb to match
the new deadbolt location. Fill and paint the old strike plate
location. If the finish isn't paint, leave the old strike plate in
place.

But the
latch hole matches perfectly when measuring down from the top of the
door so if I have someone build down the door frame, this could work.

Can a hole be filled in such a way that would not be very noticable
with a clear coat finish?

Short answer: No
Longer answer: You can either make it obvious*, disguise it, or cover
it up. If you patch it, it will always be detectable.

Can a good carpenter modify the door frame so the door will look good
and work well? What should be done about the missing 1/8" in width?

* First rule of decorating: If you can't make it match, make it stand
out.

--
Steve Bell
New Life Home Improvement
Arlington, TX