We offer used mainboard / logic board for the iMac 27" A1419 from late 2012. The logic board setup is with:

- 3.2 i5 CPU 
- GTX675MX 1024mb GPU

Details:

Apple Parts number: 820-3299
A1419 - 27" - 2012 - 2k lcd model

Correctly working. We also have parts for other models.