Thanks for the update. I guess since Finium is targeted at automotive production one will have to be lucky to find any.
I hope you are pleased with the 3M lapping films. They are more widely available and you can find reference to their use fairly easily. The lapping films are designed to produce a very even and ultimately polished surface for sample preparation, rather than “high material removal” etc. I have used them to sharpen a straight razor with middling success but I haven’t compared them to anything else for that purpose.
The 3M microfinishing film should be more similar to the Norton Finium product. I have never used the alumina version but I have brief experience with the 3M diamond MFF. My initial impression is positive but given its high cost I am not regularly using it.
The Finium marketing would have one believe that it performs exceptionally for an alumina product. It seems to be placed in a higher tier than their Q131, Q132, Q151 alumina microfinishing film.