Well, it’s not vintage hand wired, but I like both my PF20 and PF50’s a lot. My PF20 sits in my living room on top of a PF112HLF, which is ported, and it sounds great for lower volume practice. The PF50 (I now have 2) is nice in my garage running through either the PF115HE or PF210HE, both are sealed design (although the lid is removable and you can attach the PF20, or 50, or any of the class D PF350, 500 or 800’s). The 115 is richer sounding, while the 210 is a bit tighter and mid focused. The other PF50 stays at Bad Lemon studio and is used for recording. It sits on a PF115LF, which is ported. Both the 20 and 50 have a xfmr balanced out that is getting the post power tube signal, and they can be used with no speaker plugged in, so it’s great for recording drums while playing along with headphones only, and getting a rough bass track down.
I’ve heard it said that the PF20 is designed to be close to the B15, while the PF50 is supposed to be close to a V4B.
I’ve had an early 70’s B15 and I liked it but it had no mid control, and it had two channels which I had no use for, one channel is enough. What I did do was patch the channels and set channel two for a mid-rangey tone and then use the channel 2 volume to blend in that mid tone.