Coats tire machines?

[torredcuda]

I`m looking for an old tire changing machine for the garage just to mount and dismount tires on steel rims.What are the differences with the Coats 10/10,20/20,30/30 etc. models and which one would be good for my needs?Any other brands/models to look for?

[Chryco Psycho]

not sure on the differences , Coats made a decent machine in the day though 
 all the newer ones do ot put pressure on the rim so anyhting newer si better & with the tough times I bet a few will come up at auctions