I did a search on "parallel flow condenser" and came up with ackits.com and acsource.com

There was also someone who bought one on ebay that would need to be adapted to fit the MB hoses.

Good luck! Let us know how it turned out.

__________________
Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)