OWWM.org has a specific section for buying and selling old metal working machines, although their primary interest is old woodworking machinery, hence the name.
Homecraft was the homeowner/hobbyist brand of Delta in the 1950's and early 60's. Heavy, all cast iron. Go to OWWM.org for any and all questions. Also will be able to acquire any parts that you might need. I've got a Homecraft 8" table saw and 9" sander. Great machines built in the USA.
Citric acid. Find it in the canning section at your local grocery store. It's a powder, just pour into water and walk off. Next day and done. OWWM guys use it.
I took down a 75 year old barn last fall. 30x40. Rented a scaffold and wore out a $20 Harbor Freight recip saw. Very doable. Kept the wood, using in my new barn/shop.