the 'soldano modded marshall' is probably incredibly similar to the SLO. it has an added valve, which was a popular mod at the time, but the circuit is still very marshall-esque. While the 5150 wasn't a 'clone' so to speak, it definitely has elements in its circuit which were things more unique to soldano, as well as features which related closely to the SLO. The 'soldano modded marshall' I'd imagine, is quite similar to the Avenger minus the Depth control. The 5150 is even further away from a marshall circuit than the SLO is.