1372 built
That's the number quoted, to include all three types (M26, M26A1, M26A2) No-one quotes an exact split of the types, as some of the early ones were later rebuilt as M26A2.
Armoured ones tended to end up in Europe, (France, italy, Germany, Scandinavia) where they are not that uncommon, although the supply is drying up. Most of the ones left in the US seem to have been either soft skin as built, or rebuilt as soft skin later on, hence all three mentioned here are soft skin.
Probably a few armoured ones re-imported to the US recently from the European stock.
Not aware of much NOS, though dealers like Army Cars (in US and Europe) and Jaap Rietveld would know.
If you run across one and can't afford to use it, I'd still grab it and throw a sheet over it for the future, even if it won't drive.