http://www.mylincolnelectric.com/Catalog/operatorsmanualdatasheet.aspx?p=28744exciter field coils L8707. The only diference is the way they're wired internally in the field housing. Thus the reason you have to turn your rheostat to 100 for full output on the older machines and not on the newer ones.
New with 1 year warranty ( if properly installed) $245
Have you lost 110? and thus lost weld? Email me and I will give you the ohm readings to check your coils.