Yup, what Puc says!! Myself, I would make up a 50/50 mixture of ATF (which is pretty much what Marvel Mystery oil is) and brake fluid or penetrating oil (brake fluid is a wonderful penetrating oil and rust eater), and pull the plugs and using a syringe as Puc mentioned, squirt about 5 to 10 cc's into each cylinder and let it sit for a day or two. I would, at this time, drain all that 30-year oil out of the crankcase, and let it drain for a day to get all the nasty sludge as well! I would then find some inexpensive 10W40 oil that does NOT have any friction modifiers in it, just to use for a little while, like as long as it takes to get the engine running, then dump that oil as it will be contaminated with rust and gunk. Now, just as Puc said, once that penetrating mixture has sat for a couple of days, disable the ignition and fuel line and crank it over and over and over to hopefully clean up the piston rings and cylinder walls before you actually try to get it running...
There is also an old school trick of mixing kerosene in with some oil to turn over the motor (and maybe run it for about 15 seconds) and then drain that mixture for a good day to flush out the rust and sludge if you are brave, but I'm thinking hopefully with the very low mileage on your motor there should be very little actual sludge, just the possibility of a rust buildup...
Best of luck, pretty much plan on rebuilding every caliper and master cylinder as I'll bet you dollars to donuts you will find a crystallized mess in them...