My $200 RS1400 was near as purty as yours! I asked the importer for his cheapest 5 ft tiller and he showed me the one along the back fence, the one he said was too dinged up to repaint. Fine, sold! I didn't buy it to put in a museum. It works fine.
The seller threw in a set of new tines that didn't look much different than the two lowest tines I see in your picture except the metal is thicker. It seems to me that wear makes the tines a little shorter and a lot thinner, until the tips start snapping off. I still see some curve in your tines so I assume they would work ok. I would just replace the few missing ones.
Maybe you have seen this in some of the old threads here: the one point that may need attention in these 25-30 year old tillers is the off-side axle bearing. It may have been sitting with water in it since the tiller was retired 15 years ago. One dealer said to toss that old bearing and put in a new sealed one before it seizes and chews up the end of the axle. I really should check mine, at least repack it, but I haven't. Over on the oil bath side and up top by the driveshaft, nothing should ever need attention beyond clean gear oil.