ggood

I have a 1978 280Z with 144+ miles that is a fair weather driver. I've added new carpet, seat covers, dash cover, headlights, tires, hood latch cable and bra. It runs great and when I had the oil changed the machanic I take it to (only does Japanese imports) feels it leaking oil from the rear seal and probably is getting oil on the clutch. Also leaking around the valve cover. His estimate is about $1000. I do have some minor rust behind each front rocker panel otherwise it looks very good. Again, runs strong and is fun to drive. Should I invest in getting the engine work done? Would rather spend the money on rust repair and save for a total repaint. Any advice would be appreciated. Thanks