Genuine liverpool Binns Rd made Meccano can be purchased from a number of dealers,from near mint to well used,and in a variety of colours, to suit the various colour changes meccano made over the years.There are number of dealers who supply replica parts which appear to be made in India ,qhite well made,and in the last few years some enterprising people have started making Meccano compatable parts like a larger range of gears,various sizes of crane turntables ,extra long flat strips etc etc, If both your sets are in one colour scheme,probably yellow and silver ,try to keep any new parts to the same colour,a box of parts to one colour scheme is worth more than a box of multicoloured parts. The most popular colour no doubt is the medium red green,post war to the mid 1950s,then came light red green, Colour change was due to identify parts with no lead in the paint, then in the 1960s came the yellow/silver and zinc plating. When Meccano declined a variety of colours including dark yellow ,very dark blue,were used.Lash out and buy and buy little lad and yourself a no 10 set in its nice wooden cabinet anything from one to two grand ,I always dreamed of one when I was young, I always kept my Meccano,and was near retirement when I sold my dinky collection and made up my existing meccano into a no 10 ,dream achieved,then I kept on dreaming until I got a lot lot more meccano.Best toy ever made,it taught me a lot about engineering and gears and gearboxes and it all started when father brought home a shoebox of pre war meccano. Google "the Meccano web ring" it has about 100 site ,including dealers and lots of information worldwide on meccano .