This is meant to be the same bike (seen earlier) ..although it has a different number plate? Matchless G3LS if 350 or G80LS if 500 It has jampot rear suspension and full width front brake so is 1955.
The dual seat got messed up in the crash, of course. Heaven knows what detail showing on the tax disc (not seen in the on-road shot) as front and rear numbers don't appear to match. Presumably DTR 850, rather than an anticipated 1965 plate.