Build your network and deals will come out of the woodwork. 

We have had a very tough time securing materials for our Fine Woodworking courses (residential construction and cabinet-making).

If the jamb wood-work and overall ascetics of the woodwork are good and wanted to be kept, I would do that via first opening all the interior case trim of windows, insulating via closed cell expanding foam (NOT open cell, specifically closed), and than reinstalling all casing.

@Johann Jells I hate painting any woodwork that has been stained and finished-shellac, varnish or oil.

UNIQUE TRANSITIONAL CONTEMPORARY WITH STAINED WOODWORK THROUGH OUT.

I always try to focus on adding value before thinking about anything else.....understand how you can help them and then, your mentors come out of the woodwork.

Home was in very rough shape and had been neglected for 20+ years, but did have a nice kitchen and main floor bathroom, large lot, and amazing original woodwork.

I'd love to approach investing the way you are describing here, but my main downfall is that I really don't have any handy-man skills (really regretting not taking woodworking and construction in high school, lol).

And, your tenant's theory on why the door is damaged is pretty spot on:"If there isn't enough ventilation in your bathroom, the humidity in the air can wreak havoc on woodwork such as vanity doors. ...

On the other hand, no one comes in to rent an apartment and doesn't love the large windows and woodwork so we get lots of interest over the blander places.