Painted is easy to fix, clear finishes are harder.

A decent painter should be able to repair either.

Where is the veneer coming off? If it's along the bottom you might install a brass kick plate (a plate about six inches high across the bottom of the door). Paint the door first to seal it as much as possible. If the problem is elsewhere, could you post a picture?

The door is not painted, there is a finish. The veneer is off the bottom so maybe the kick plate is the answer. Is there anyway to revive the weather-beaten finish?

Are you looking to refinish (strip, sand, stain, varnish) or repaint? I've only done repainting which is pretty straight forward. Perhaps someone else here can advise on refinishing in place.

I'm guessing the veneer if it's lasted this long is not wood. From the 1900's the only thing it could be is
bakelite or phenolic. It was the first plastic.

I have not done any research on reviving it. I do know
from my background as a scientist that phenolic is a very
resiliant and hard to damage or deteriorate material. So
bringing back it's finish might not be impossible because
it's the same through and through.

However I've never heard of reviving phenolic veneer.
There is undoubtedly a 'phenolic association of america'
or something similar .

Big companies like
Dupont / Occidental / Sumitomo all make bakelite products still. If you get in the door you'll be tossed
out unless you represent yourself as a commercial account. What you'll want is to find a commercial , large city (Los Angeles or NY) supplier who has access to people
who know people who can put you in touch with the right
methods.

Or you could do what I would do. Research it online using
the keywords of

bakelite veneer
phenolic veneer

Last note: I could be totally wrong as to what the material
is made of. If you have some to test you can try putting
a flame to it. If it does not burn but smokes a bit with a
slightly sweet smell it's probably phenolic. It would also
snap like cheap plastic if you bent it.

I'll put you in my 'look in on this thread' file.

Good luck.

Andre

Suzan,
It might be easier to find a solution to your problem if we could see a closeup photo of the damage on the door.

It is very possible that a century-old entry door to a significant structure could be veneer. I am familiar with a mansion that has a very large and thick front door with 1/8" thick quartersawn oak veneers on both the inside and outside, over a white pine substrate. The door was installed during an 1886 remodeling. Of course, the door has survived in beautiful shape because it is under a protective porch, faces north, and has been cared for.
Casey