Hey Bonzo,
Yeah, for sure, I agree.
Funny you mention the 300b. Before we moved to the continent I investigated commissioning a set of direct-coupled power amps from three builders - JC Morrison, Thomas Mayer and Aldo D’Urso - based around the 300b ala WE. None of them were prepared to make a 300b amp unless I was prepared to go all in for transformers costing more than the Shindo/EAR I was using at the time (that, and Aldo was not a fan of using interstage transformers, although I hear through the grapevine he's recanted his oath). They mentioned there was a reason the WE stuff had serious iron to begin with and suggested if I wasn't prepared to play with the big boys they could make a far better amp for less from lesser tubes with better circuitry. We abandoned those plans once we discovered we were moving. It’s possible the Lampi isn’t the ideal platform for a 300b, but that’s conjecture on my part. I bet the Silbatone 300b is killer, but then, it should be.
Incidentally, one of my favourite guitar amps is built around the EL84 (the Matchless HC-30), but I understand its limited appeal for hi-fi.