Right then, You have a Full Colonel with Staff Gorgets on his collars...
The "new" pic may well be his father if anything....A captain on the General List, and of a much earlier date.
The General List is for officers not regimenatly employed.
Interesting array of medals...
From left to right...top row...

Possibly OBE/BEM ?
Kings Police Medal
WW1 War Medal
WW1 Victory Medal
Bottom Row
General Service Medal 1918-1962
1939-45 Star
Burma Star
The Oak Leaf is for Mentioned In Despatches, and would be worn on the Defence Medal