A bit of a mystery. This is clearly a scrap line (the connecting rod is missing from the loco 80099 in the foreground), however 42482 in front was withdrawn off Chester and stored there from April 1965 until September when it was sent to Cashmores Great Bridge.
6611 was withdrawn from Croes Newydd in November 1965 and stored there for only a month before going to Birds Long Marsden. Therefore the two engines should not have been seen together when withdrawn.
80099 behind was withdrawn off Machynlleth in May 1965 and observed stored at Chester in June 1965 therefore this must be Chester and 6611 is still in service awaiting repairs - perhaps they never happened.

Additionsl informstion is that all three locos were recorded on Chester Midland shed, May 9th 1965.