Maybe I am just overly cautious but if I had a $25,000+ gun--
Call me a wuss but I doubt I would be putting full bore solid loads thru it. Even Woodleigh solids can damage old bores not on spec.Might damage that $$$$ rifle.

I would load my Merkel to full factory velocity and have few concerns before I would put a 70-100 year old "best" rifle with old steel thru multiple max loadings.I may be the exception but I would want to preserve the "best quality" rifle as an investment that appreciates.

It all comes down to money and what you wish to risk.If I tear up a Merkel Chapuis or Heym it can be fixed.Not so with a "best" Brit Rifle.