Pentax K1000 "history" top plate design

I recently acquired three Pentax K1000 cameras and although I've seen
over a hundred of these in the last few years these are "different".
The pentaprism has PENTAX but does not have ASAHI or the AOCo
trademark. These are NOT the last incarnations having plastic top and
bottom plates but these have the metal bottom and top plates. The top
plate appears the same as that of the 1994 Anniversary Edition which
was sold in Italy.

Several references point out 3 main models.

The first two have top plates with the word ASAHI above the word PENTAX
on the front and the AOCo logo on the slanted part over the pentaprism
as well as having ASAHI OPT. CO. on the rear of the top plate, advance
lever side.

The 1st model has the serial number on the rewind side of the top
plate.

The 2nd model has the serial number on the bottom plate.

The 3rd model, with top and bottom plates made of plastic, omits both
the word ASAHI and the AOCo logo as well as omitting the ASAHI OPT. CO.
designation on the back of the advance lever side. This model has the
serial number on a black plastic strip affixed to the bottom plate.

The serial numbers on the three cameras are 8351550, 8360195, 8386037.
If anyone has one with a similar top plate I'd like to know the (first
digits of the) serial number. I also have one with the "regular" metal
top plate and the serial number 8318038. Are there any 832xxxx serial
numbers out there and if so, what's the design of the top plate.

Thanks,
Pat