Weird Rock Ola - NPM trigger housing?

[CrossedCannons]

From the description

http://cgi.ebay.com/ws/eBayISAPI.dll...m=350362795817

AUCTION IS FOR ONE VERY NICE CONDITION USGI TYPE 2 ROCK-OLA/NATIONAL POSTAL METER TRIGGER HOUSING.ON THE LEFT SIDE IN THE RARE VERTICAL STAMP ROCK-OLA. ON THE RIGHT SIDE IS STAMPED N16. EITHER MAKE BY ROCK-OLA AND USED BY NPM OR THE OTHR WAY AROUND.

How did this come about? Is there any documented basis for this type of "integration"? If so, where?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[BrianQ]

They are not rare and not early.

[CrossedCannons]

Thanks Brian. I'm still new at this and it just struck me as odd. So how did it come to be? My ready-reference, War Baby, records no exchange of trigger housings between these two primary contractors. While I've still got a 6" stack of newsletters to go through, so maybe I'll find an answer there, that's a rather slow and laborious process (about an inch per month).

[BrianQ]

Not all the parts integration data is printed in War Baby! Rock-Ola also received trigger housings from other prime contractors.

[DaveHH]

Came with an N16 Trigger Housing and it was one of the last group made in April of 1944. What puzzles me is with the apparent thousands upon thousands of fabricated trigger housings being made by IBM, that a milled TG would wind up on a late production carbine? They were making 4,000 a day in Jan 1944 and a total of 400,000+ during their contract. I assume that some manufacturers (Inland and Winchester) simply refused to use them?

[CrossedCannons]

That's interesting. My Underwood (early 1944) came with an N16 trigger housing too! Is there any "translation" between NPM's lot numbers and dates? While I seriously doubt it, could this trigger housing be "original" to this gun?

[BrianQ]

They are not lot numbers, they are revision numbers is a date connection.