Could we build an even more Modified Hall?

I RECENTLY found this drawing in my files depicting the last Modified Hall. It shows the locomotive with outside valve gear, as proposed by BR for the last batch.

In the end this idea was abandoned and they were built with the original GWR system but with plate frame bogies and frame extensions. I got to wondering if there is still a Modified Hall yet to be rebuilt from scrapyard condition, because if so this alternative version could help to fill in yet another GW locomotive gap and attract money to the project.

I suppose you could build one from an original Hall by using false frame extensions and creating a new bogie. What do other readers think?

Clive Thompson, Wroughton, Swindon