Lamp with dimmer - old or a late copy

Hi,
We've had this lamp for a few years and it has suited it's purpose well but we would now like to change the decor to suit more modern lighting. I actually bought it at a boot sale and found that on returning home it needed a small repair to get it working. Back to the point - do you think that this was a 1970's original or a later copy. It has no makers marks or labels. My feeling is that it is a late copy, what do you good people think?

Thanks,
Bryn
Strewth this image is BIG what do I need to do to make them smaller?

Hi Bryn, sorry I missed this thread until just now! Anyway, in reply to your question, my gut feeling is that this is probably later than 1970s (i.e. 80s or 90s production).