X61 second fan FRU

[unixed]

I have an X61 with a second fan. The hmm lists the FRU as 42X3806 and that of a "Second fan, low profile" as 42X4678.
I've seen a second fan with FRU 42W3410 being listed as for both the X61 and X61s.

Can the 42W3410 FRU fan be used in an X61?

All the second fans I've seen are Toshibas, are there no alternatives using Panasonic for example, like the Furukawa heatsinks for the T61?

Is there a way to avoid requiring a second fan (beyond pressing ESC at startup)? A search of the forum shows a post by WileE pointing to http://forum.effizienzgurus.de/showpost ... ostcount=8, but that link is no longer available.