The exhausts can be simulated with styrene or brass tube easily enough. The road wheels are a little tougher, I filled the strength webs on the kit wheels with putty then sanded to get a smooth wheel. Then I wrapped a thin strip of lead foil around the outer edge of the wheels to simulate the steel running surface. Styrene strip would work too I think. The return rollers need to be cut off and three of them relocated as shown in your ref pics. That's about all I've got on the conversion, of course when I did mine I only used the Tamiya kit. Dragon didn't exist then.