Is this MAX31855 or MAX6675?

Riva:
If it has a MAX6675 on board then it will function as that instead of the MAX31855.
A quick google finds this that seems to indicate the MAX6675 is obsolete now and does not cover as wider range of temperatures as the MAX31855.

Yes, that's what I gathered too since I posted here. I tested it and indeed it is, as I feared, a MAX6675 board. Sadly.