Guys I've been researching hbt pants here on the forum. I had recently picked these up, nice overall, gauze tag under pocket now blank. Are these of the WW2 era? 

 

 

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These trousers are a late WWII production variation of the Trousers, Field, Cotton, OD Quartermaster Spec P.Q.D. 371C (known to collectors as 'M1943 Field Trousers') made out of herringbone twill fabric rather than the usual sateen fabric. These trousers are also sometimes found made of sateen but with pockets and interior trim made from HBT fabric.  This and the 13 star tack buttons rather than plastic buttons were production allowances that would have been approved by Quartermaster inspectors due to shortages.

 

Trousers, Field, Cotton, OD were produced again during the Korean War era but those trousers were made to a revised specification that have waist adjustment tabs that point to the rear rather than pointing forward as on pairs produced under the WWII specification.

 

Although these trousers are made of HBT they are not the same as, and would have been issued differently than, the Trousers, Herringbone Twill of various specification numbers including the early Trousers, Herringbone Twill Spec QMC 6-254 with internal pockets or the more commonly encountered Trousers, Herringbone Twill, Special, Olive-Drab No. 7 Spec P.Q.D. 42C with the larger external pockets and gas flap.

Well thank you very much for this information, I was almost sure they are WW2 but wanted to hear more information it looks like I got it 😆