If it is the Rouse car, then that's a heck of a discovery....
Pic shows a Rouse XR4Ti at Donington ETCC round 1986- from memory, 2 cars were built in 85, one subsequently ended up in NZ/Australia
http://www.racingsportscars.com/etcc...-04-06-032.jpg
First thing that leaps out at me in the pics of your car is the recess in the front wing for the extinguisher/electrical cutout switches which is in the same place as on the Rouse cars (think these were in a different place on a LHD Eggenberger shell).
Eggenberger car as a comparison
http://www.racingsportscars.com/etcc...-04-06-003.jpg