Rupp twin engine Dart karts,Show and Tell

I picked up a couple of Rupp dart's. The first kart is in MI and I'm in IN. and I won't get my hands on it until June. The second one I picked up in a trade a couple of days ago here locally. This one is missing some pieces and has a few add ons but is a very good and solid chassis. I haven't decided on whether I will leave the add ons or not. They are well done and show some of the karts history. The guy that I got the kart from said that it was in a building in woods of a property that someone else had just bought and he got the kart from them. Is there traits to tell a early Dart from a later ? And there were different models of Darts,anyway to tell what's what ? Did Rupp stamp any numbers or identifying marks on these karts anywhere ? On to pictures. The first 3 are the kart,engines and parts that I bought but won't be here for for about a month and a half. The rest are of the kart I just drug in over the weekend.


It appears that at least 2 of those engines are Jacobsen model j321, probably from snow blowers.
2.5 hp and very robust.
I have one mounted on a '68 Fox Doodlebug.