Is your front mounting plate drilled for bolts? If not they can be drilled. Locations in the Tech Tips
http://www.stovebolt.com/techtips/motormount_235.htmlDo you have any of the parts from your 1951 engine?
Tech Tips on parts in the assembly.
http://www.stovebolt.com/techtips/engines/motor_mount_front/index.htmlRear motor mounts as Im sure you know are on the bellhousing and all of the vendors have replacements
Ebay has several listings for complete front mount setups including the front mounting plate, and the hard parts between it and the frame. All of the vendors have the rubber insert