Martin 250CE turret part?

[Denys Jones]

Recently a donor presented four items as in the photo.

The bottom three have been positively identified as coming from the Martin turret but I've had no luck establishing if the fourth does.

Can anyone assist?

TIA

 

[MiTasol]

There were multiple versions of the Martin 250CE turret and unfortunately I do not have any manuals for any of them. There were also a Martin hydraulic, ball and tail turrets which may or may not have shared some common parts.

You can probably find some manuals online but this one may help if the item shows in photos - 250CE starts on page 71 of the 1946 turrets section. Aircraft turrent documents

Some Martin turret manuals are