This is from the WRA docs that have now been published online from the Cody Museum. From the Marine, WRA, and Army docs the heavy barreled rifles never materialized. The Marines did buy small lots of heavy barrels off WRA but it was for their rifle team rifles, not snipers.
There were more than 926 total A5 scopes bought by the Marines in 1917/18. 926 was just the delivered portion of one contract the Marines had on A5 scopes. They had more than one contract.