I have listed an RM6 Chassis and speed controller on Ebay.
The RM6/RM7 chassis cars were the Toyota Toms 84C (which this chassis was ), the Porsche 956 and the Newman Porsche.
http://www.ebay.co.uk/itm/2809943636...#ht_500wt_1204
http://www.ebay.co.uk/itm/2809945293...#ht_500wt_1204