Classic car seatbelt and brake test.

I have two classics here that have been off the road for a number of years that I want to check a couple of things on before I buy parts to put them through the test. 

First is a 1967 DAF 44 Variomatic. 

Two questions for this one. 

First the vehicle has no differential instead using independent drive to each rear wheel. Cornering is facilitated by one wheel being able to be in a higher "gear" than the other. Because of the vehicles design a rolling road brake test would put a lot of stress on the transmission likely resulting in broken belts or spinning out the rubber propshaft couplings. Is there anything in the manual that allows a belt driven car to be tested other than on the rollers. 

Second. From the factory the vehicle was fitted with 2 point diagonal fixed seat belts these are frayed and will have to be replaced. Can these be replaced with original equipment or will I have to adapt the vehicle to take 3 point belts. 

Second car is a 1974 Triumph Spitfire. 

Only one question again seatbelt related. The car came out of the factory with inertia real belts but is currently fitted with fixed 3 point belts. Will these pass or do I need to fit inertia reels?