– E.M. release unit type N MARK 1 and
– E.M. release unit type AIII DRG-number 10750 REF 11A-552

The E.M. release unit type N MARK 1 can be fitted to the Avro, Universal or any similar type of bomb carrier for loads of up to 1,000lb.

The E.M. release unit type AIII is for use with Light Series Carriers, i.e. for small bombs, incendiaries, flares, smoke floats, marine markers, etc.

The carrier in your larger photos looks like an Avro Standard type, albeit stripped of parts.

You are also showing a 4-way Auto Selector Switch (the box with five leads out of the bottom of it). This would often be found attached to a Light Series Carrier, although the Type C version was used on rocket firing aircraft.

Next to it is an E. M. Fuzing Unit, one of Types A,B,C,D or E depending on usage (they are all similar). Pretty much a standard fit on most bomb carriers.