Holly smokes machine peoples, Utilathe heaven! The green ones in the middle picture are 1950's ' Utilathe' models. Probably 12" x48". Maybe 13" for this vintage machine. I doubt if they are 11" swing. Standard Modern lathes were a mainstay in Canadian and US ARMED forces for generations. When the company sold out and moved to the US, the US conglomerate basically killed the product line with bad customer service and gold plated prices.
Having said that, I have one just like in the middle photo and love it. Unfortunately mine was used to keep the Canadian Navy afloat and operational for 30 years and is seriously worn out. Yet I can still easily take a .100" cut in mild steel stock with a 1/2" HSS tool bit and the machine just scarfs it down without a thought at all.
If these were truly school lathes, and never used for production work, it might seriously be worth calling the Roberts company, or flying in to look at them. Surely with a dozen available, you could find a decent one to take home. $1800 to $2500 isn't a bad price here in the pacific North West - if the ways aren't worn Badly and the headstock doesn't growll so much you can't hear yourself think.
Only drawback is the spindle takes a D1-5 camlock chuck. Hard, hard, hard to find. Not impossible, but not much selection of chucks available these days for d1-5. Don't know why.
Parts are still available from a Canadian distributor - I just had them make a new specialty gear in the apron to drive my lead screw. One week turn around.
So overall, Definitely worth looking at. Actually I think I will call these guys myself and see what they say. Love to upgrade mine with a better machine.
Glenn in Seattle.