the fab shop i used to work for had Cobra liquid cooled wire feed units they used for aluminum...with good results
That looks be a Cobramatic wire feed unit. It turns any welding power supply into a MIG. The company is still making them, but they are different looking now. The ones I have seen have pull-guns, so would be ok for welding Aluminum. The Miller looks like an older arc unit. I would make sure that you can still get supplies and spare parts for it. http://www.mkprod.com/Prod_sub_CobramaticSys.htm
thanks for the replies , I guess i`ll have to get off my lazy ass and go look at it.....ad says $250 , not bad if it works.
It is a CobraMatic wire feed, generally they have a push pull set up so you can use large spools as well as larger diameter wire for aluminum as opposed to the one pound spool guns. They are still available from Lincoln and are listed in there catalog I have a very old one that I use all the time and can still get parts for as well as consumables. Remember if you want it for aluminum you need an AC power source(welder) Hope this helps