I seem to remember all of my old novatron (iamm) players (those with Sigma 8621) played both wmv7 and wmv8.
I had a bunch of academic videos from ffh films that were in wmv8, and the novatron players of the day were the only ones I could find that played them.
The novatron Sigma 8621 reference design was found under brands such as mvix, klegg, cibox and others.
I don't know if current novatron players will play them, as novatron kinda lost their way and isn't so popular anymore.
If you have a sample, I could test it to be sure.