Chris, I did buy that one and it is being rebarreled and new forend and case coloring.
It will be a 450 3-1/4 BPE though.
I have the Metford barrel to use and I really wanted to go with a 500/450 of some sort but the trough in the action is really too small for that size of rimmed cartridge. Externally, the barrel will be turned to match my 461 and to use the original rear sight that is on the small barrel. I'm really glad that sight was still with the gun!
I didn't have a Selous plated Gibbs before getting this one.