You might be looking for the old P/N 778521 … this is no longer available from the OEM.   RIGAS manufactures a replacement case heater asembly (p/n: 65B0001).   Our unit uses a Dywer Instruments digital temperature controller which makes it more accurate and more stable than the original analog controller board.   Our assembly includes: heater, digital temperature controller, fan, RTD, bracket, power cable (harness), installation instructions, thermal fuse, and fan guards.  No new mounting holes are required;  our unit has the same footprint as the 778521 assembly.    One wire (for heater “on” indication) has to be relocated.
We build these on demand; it can take a week or two to manufacture.
The price from the OEM back in 2003 was approximately $1100.  Our unit sells for $1500.
Call us at 877-616-0600  and ask for p/n: 65B0001!!