Well that depends on what you mean by intervention.... If you go to MyLargeScale.com and go look in the masterclass thread, you will find a series there by David Fletcher on how to build a laser cut model of the M&SV combine in proper 1:20.3 scale. The combine and a Carter passenger car used to be available in both North America and Europe as wood kits. Here they where available from Bronson Tate, but he has stopped producing them. I understand they are still available from Europe. Germany, I think. These courses where intended as open source, so you could download the cad data and find someone to do the cutting for you. i have a friend who is a member of a maker club that has a 60w laser cutter. I have built two cars now from styrene. I am in the process of building Dan's E&P combine to 1:20.3 scale. (it is an interpretation developed from estimated sizes) If you look up MikeL on mylarge scale you should find my baggage car.
Mike