Hi Terry ,there are plenty of polystyrene caps about but I have read that the film manufacturers have ceased making it some time back ,and that a couple of companies do have a stock of film and possibly manufacture for specific orders .But as far as I am aware most of the polystyrene caps available today are NOS .
Steel leads are one of my pet hates . Even the newer Vishay Roederstein 1837 have steel leads along with many other cap manufacturers .They don't even state it in the data sheets
. Panasonic HFQ ,FC ,steel also .
One of the reasons to search out NOS caps is that many of the new ones are using copper clad steel ,unless you go for specific audio caps which usually use ofc copper .
After using nice copper caps I cant understand why manufacturers haven't filled this niche in the lower end of the market with lower voltage caps .There are a number of copper film caps but most are very expensive boutique caps .Too small I guess .Or maybe the light hasn't come on to the potential .
These are Japanese copper foil polypropylene 0.01 ,and really beautiful sounding .I would get a hundred if I could .
They were probably a small run custom order as the only markings are written on with permanent marker .