Clutch and Fan: Thanks to a member on FBBO, I was able to acquire a correct 18” clutch fan #2863215 (the numbers can be found on every blade).
Even though the fan was in good condition, I measured and marked every blade on both planes and corrected some blades a few mm. Once the fan was again in perfect shape, it got bead blasted and painted.
Correct NOS fan clutches #2863266 are hard to find and if, quite expensive, so I went with an alternative: https://www.rockauto.com/en/moreinfo.php?pk=815318&jsn=656
To my luck, the previous owner preserved the original and correct 22” radiator and matching fan shroud.
The direct fan which was installed before is now up for sale.