took me years for find one of these, i had seen one when a kid. The cap looks 100% atlas to me, i've got a feeling this is a re branded Atlas tube made for Crompton?

I think i have a Crompton with this etch somewhere i think it is a 5 foot, im assuming fairly old?

I've one in 3' 30W T12

I have one in 20w and 3 in 15w t12 I do like this etch style.

Yes this is atlas Phil. There was a about 4 years when these were not printed with a date code. If I am correct this is between 71 and 74. So this tube will be from the 4 years no date code printed on them time. As I say, no elma date code so I cannot give you a Defo mfd I've got 2 of these in 3'30w