Very nice find. As far as the motor how many miles on the car? do you know the history? do the miles on the motor match the odometer another words not rebuilt? My suggestion would be to fully assess the motors health before touching it. as far as a compression and leak down test it can be misleading on a engine that has sat for a long time because of rings sticking and valves not seating fully because of rust. I always recommend to put as many heat cycles and miles on it that you can to give it it's best chance before doing those tests. Change fuel pump and all fuel line hose. make sure tank is not full of rust and stale gas n water. Rebuild carburetor, flush cooling system and replace waterpump and replace all hoses and belts and of course a full tune up. As far as the lifter tick it is common when a motor sits for a long period, if it won't quiet down add some marvel mystery oil to the crankcase as it has a high amount of detergent in it and will usually quite noisy lifters after a while. Also make sure when you change the oil to use high zinc oil or the separate zinc additive if you already changed it so as not to wipe out your camshaft. These are some of the things you do to resurrect a long dormant engine. As far as the oil leaks I would totally degrease and wash the engine and go from there as many a mechanic has been fooled into thinking they have an oil pan leak when it was something else up higher and gravity just takes it to the bottom.