Richard as it has quick release fasteners it will have been around a part that needed regular access- This is usually engine cowls.

The circular external reinforcer is not the same but similar in design concept to those used on Anson, Oxford and Tiger Moth so a 30’s not high speed design is where I would start looking.

As to the part number I don’t recognise it and the inspectros stamp ?ALS woudl imply a sub contractor.

B-17 G

Tail Wheel assembly G3-217A

Tire 26 inch Spec AN-C-55 Type 1

Tube 26 inch smooth contour Spec 2650

P&P I have a small reminder on the wall behind my desk –  the remains of one of the steering fins from the V2 fin.

In addition to the graphite  in the main exhaust to steer the rocket, on each of the fins there were these flying control fins. They are easy to see by the bulge in the fins where the chain drive went down to a sprocket that was attached to the splined shaft.

This one was launched from Holland at 11 p.m. on Christmas Eve but landed in parkland in North London and this piece was blown off.

The green paint is original.

A section of G-ACBH is available here:

https://antiqurio.co.uk/product/blackburn-b-2-g-acbh-top-fuselage-skin/