Peter ~ You might try researching
Vintage Machinery. Excellent website for older equipment, especially those that have gone out of production.
This is an introduction about Ram Tools on the Vintage Machinery website: "This maker of handheld power tools and bench grinders was founded sometime before 1946 and was in business until being acquired by Bison Gear & Engineering Corp. in 1987. We have seen "Ram Power Tool Line" products from Thor Power Tool Co., but we do not know if there is any connection to Ram Tool Corp."
Edit: I just checked the Vintage Machinery website and found this statement: "Handheld power tools are outside the scope of this web site. Please do not ask us about, or upload pictures of, handhelds!" You may be out of luck with an inquiry at VM, but you might want to check out Ebay.
Good luck hunting.
Bob