Both bodies are related in that they originally came off another replica. The yellow one has been completely redone and is available as a Thruxton GT from JW Engineering in St Austell
http://www.thruxtongt.co.uk/
It will be available as a lightweight Ford based track car or a BMW based tourer with doors and windscreen etc.
The MK one has a shortened bonnet and was developed by Pat Jackson.
http://www.driveaction.co.uk/hsr/hsr.htm