Q: Are there any secrets for salvaging old hardwood floors? Also, do you recommend resanding or keeping the worn wood that shows now.. for resale?
A: Secrets? No secrets. Just a strong back if you are pulling up the floor. 3/4 thick is certainly worth saving.
If it is the old 3/8 thick strip, it isn’t worth it because after it is re-installed it would still have to be sanded flat. There wouldn’t be anything left of the 3/8 in that scenario.
I would pull up a 3/4 floor, pull the nails and scrape clean the tongue and groove of any finish and grime that has found it’s way into that area. Re-install the floor in a new location and have it sanded flat.