Unknown 2pdr Pom Pom (?)

[bacarnal]

Of the items I found at the OVMS SOS was this round that was jammed into a British 40mm II 1941 Bofors casing. I've had a few 2Pdr Pom Poms, and though this one looks similar, there are no marks on it except for the F and anchor. No kanji either. First, is it a 2Pdr and second, of what provenance? Thanks, Bruce.

 

[BMG50]

Whats the top of the shell look like, could be a 2 pounder naval star shell.

 

[bacarnal]

Here's pix of the nose and base. I'm leaning towards HE since it is threaded for an SD Tracer unit and the nose has threads and a set screw hole. Thanks, Bruce.