heater matrix 300tdi

I have a leaking (since bypassed) heater matrix in an auto 300tdi with A/C. It appears that the matrix for Td5 and D1 are the same unit. Does this hold true with the A/C ones? And what is the difference between the A/C heater box and the non A/C? Could the A/C specific parts be transferred to a more recent box to save the trouble of stripping right back to the matrix ? The whole box units sell for half what the matrixs go for.

Anyone done this job ?