Consolidated B-24 Liberator —

It is indeed a very early model. From the Commemorative Air Force website: This Liberator was the 25th built out of a total of 18,482 B-24s. The total number built is documented as 19,267 with the inclusion of all variants. This aircraft’s construction was completed as serial number 18 and accepted by the British Air Ministry in May 1941. https://www.commemorativeairforce.org/aircraft/3