Chevrolet C60 twins (reposted)

[Rolf S. Ask]

Well I will try again.
I was visiting a fellow MV-collector a few weeks back, and noticed two of his CMP's.
And by chance they stood side by side....
It is one C60L and one C60S
The C60S has the following dataplates:

C60444-M-P
2844222469
PR 3848305
SM 2569
Aug 21-42

C60444-M-WIN-4

The C60L has the following dataplate:
C60448-M
2844322574
PR 3844633
SM 2654
AUG 21-42

C60448-M-STORE-2

and n the door: L 4999868

Now; who can tell me what a WIN-4 is? It has a winch in the front of the body like the derrick, but is it a derrick (or was it an auger??) Anyone having any pictures or orher information on this truck?
And I have never seen any diagram of the interior of a STORE-2, would be nice to see one.
And the SM numbers? Are they this different because they were ordered by different branches?
In a garage nearby he had another C60L (a very original and very nice one)serialnumber 2844321008 which was delivered AUG-6-42 but this one has a SM order number 2570. This makes a production of 1566 C60L's in 15 days, but again a big gap in the SM numbers (84).
And above all, he even had another truck witch has been "WIN-4"

Rolf