I wouldn't touch it for any amount of money! If it really was some prtotype TD system, it would be way more money, and much better designed!
There's no means to tighten up the mating area, and no way other than the mag tube to stop the barrel from unscrewing upon firing. (Roundsworth caught this) It not only is a poor design, but I'm not sure how well it would maintain headspacing after it had been shot a bit.
My guess is it's been made up from parts of a model 36 and a model 1893/93 rifles.
note the lower tang has also been bent to fit the wood, gives me a sick feeling in the pit of my stomach. A neat idea but poorly executed, I recall seeing one for sale a year or two ago, not sure if its the same one or not. I recall about 350 back then... one of you nice fellers told me a something a while back I'll never forget... and that is that you can't shine sh#t...
Whatever it is, there's a couple of other non-Marlin touches there.
Looks like some un-informed person used the bulls-eye for the rear swivel stud. The scope base looks out of place above that square bolt. The fore arm looks out of scale with the rest of the rifle- just some observations from someone who don't know a lot about this subject.