I have a kit of the SR 53 made by Ursus of Poland which, according to the net, is a re-boxing of the Airfix tool. Unfortunately I haven't got an Airfix original to compare it with. The AZ model is still simple in layout but has much better detail, although I do like to build old Airfix kits now and again, especially those that I missed back in the day. Wouldn't it be good though if something as rare as the Guideline missile set turned in an Eastern European factory.