Public Eye. The last series from 1975 (apparently).
I have no memory of this, merely picking it up as it was there more than anything. Alfred Burke plays Frank Marker, an "inquiry agent", who sets up in Chertsey after whatever happened to him at the end of the last series

. He gets the shit kicked out of him by Alan Lake to start with. Fascinating to see this really. It's so British it hurts. PI works out of an old motor shop? In the US this would be noir central, here it's just a bit seedy really. The antithesis of The Sweeney

. From babysitting orchids to bomb threats (from that nice Jan Leeming!!), this isn't Marlowe territory at all.
Any fans here??