I am going to look at a pretty old 300 soon. It has the cooler on the bottom, water cooled torch, and all cables. Asking $1000. Anything I should be wary of with this older machine? I will have the chance to fire it up beefore buying, but what else to check out? I believe it to be one of the early syncs due to lack of features on the newer ones, and it does not have the needle gauges on the front like some of the other older models I have seen. Thanks for any suggestions and help.