"Servicio Oficial" third overprint plate

The third plate saw use in 1952, and I do not find any of these varieties on the 5c. I find all of these on the 10c Rivadavia Brown and the 15c Martin Guemes, both on three papers: 1L (ondulating rays of 1951), 2D (straight rays diffused from 1943), and NGR (unwatermarked grid from 1945).

I think that there are two possibilities:

1: Printed stamps from when these papers were first issued were in stock and overprinted in 1952.

2: Made to order batches of the base stamp were overprinted with rolls of these papers in stock in 1952, and subsequently overprinted.

Here are the varieties;

Deformed S



Rounded L in the form of a boot



L with lengthened leg



L with shortened leg



L deformed and thin



Larger blocks would answer lots of questions. Unfortunately, all I have are blocks of four.