Mark 1 Tanks only ever had the 1 metal Abram’s and found it unreliable so rejected selling them, the Abrams that he does sell has indeed been upgraded since the 2 that I knew of now they have much more powerful chain drive motors these also use less power, these tanks are made from GRP with metal running gear and metal tracks, they are manufactured in Russia and are sold through various retailers Mark 1 Tanks, Bigtanks.de, rctanks .jp and I think there is or was a retailer in America though can’t remember who, if you find the Russian website it’s possible to deal direct at your own discretion though I have never heard of anyone being ripped off, all these retailers have their own way of dealing with customers Bigtanks.de in Germany, you place an order with him pay him and receive your tank direct from Russia if there is any damage or faults with the tank then you are rather on your own same applies if you need advice or help, warranty is very short lived and is very limited, Mark 1 Tanks you order from him pay him he receives the tank from Russia, if there are any defects he corrects them then he tests the tank to make sure all is working as it should he then ships the tank to you in full working order or you can ask for the tank in a semi kit form either way he will always test the tank this is the only way he works, I have had 2 tanks delivered this way and neither have had any faults, Mark offers a warranty on his models though as I have never had a problem you best ask him about it, I have no idea how the other companies work so can’t comment, but Mark has a very good reputation.