L-series are solid & dependable. If it runs, then drive it till the horses jump the fence. At the same time you can collect and build up a swap-able drive-train.
Two cents on smog... Having dealt with smog recently, I can tell you it's quite informative. Get a manual and do a detailed analysis of complete emissions equipment. Diagnose, Replace & Test. Not that difficult nor a hassle. Once it passes it's a matter of maintaining the equipment.
Process is expensive.
Knowledge is base so a stack of manuals is gold. Don't know if this helps but it's something.
Researching the plate number, it looks like this car was on the road at least as late as 2013 when someone made an abandoned vehicle complaint about it. It looks as if it was registered to someone named Terry Lee. Unfortunately the only photos I have left are black and white, but according to the S.F. Parking & Traffic documents, it was blue.
Renewal fees show some info. It looks like someone had its registration paid till June 2017. It's a 74 which is most likely the only reason it's been kept.