Heres one. I think pidgeon holing a venture like this into the "best sidelock only" bracket would be a mistake IMHO.
I, along with most others on this forum just don't have the means to buy a six figure gun - that is why the London makers don't produce many guns - low demand.
BUT...I would love to buy a new rook rifle or a double with less ornament than the current best guns always have. Just look at a period catalog of any of the high grade makers and wonder at the variety on offer then. Obviously, to replicate this would be impossible today, but excluding the option of offering "lesser" grade guns to willing buyers is akin to refusing money.
In the golden era of the English makers, the engraving was the least expensive task in the production of a best gun. I would bet that today, it would be the most expensive.