You may want to contact GDL (those rebuilding guys for $185) and see if you can get some kind of a deal by trading the W126 unit for a W123 unit. When I bought mine (W123), they were very accommodating, they ended up charging me about half the core charge even though my old unit was completely toasted. From what they told me, they test every unit they get to determine if it needs rebuilding. If you really have a freshly rebuilt W126 unit they may cut you a deal. It can't hurt to ask.