I'm playing an amazing 1992 Marshall model 6101 30th Anniversary 1x12, 100W combo using a 2008 Gibson Les Paul R9. These can be tweaked to so many sounds both good and bad ones. I guess that's why it's still affordable, at least in Sweden. Here's how to tweak it!
Penthode vs Triode on the 6100LM:
https://www.youtube.com/watch?v=ENi-HwPH-VI
More clips with the 6101:
https://www.youtube.com/watch?v=XNw6imi5xJY&t=20s
Here is a video of the Head version 6100:
https://www.youtube.com/watch?v=ReSw1pNhNsQ