What a beauty! I'd love to have one of those! The last machine I found at a thrift store was a Brother with way too many parts missing to make it worth my while, but I agree that it's always a good idea to look inside those cases and cabinets.
I use rubbing alcohol to clean old varnished oil and crud out of the inside of my machines before I oil them. Works great - you might want to try it to get rid of the red goo.