Well, a Hamilton Bowen conversion is a bit of a collectible, itself.

But I'd shoot it.
Is the bore .427 or .429? One problem with accuracy in .44-40's is varying bore diameter with the manufacturers. Mike Venturino has written a bit about that, but likes the cartridge when all is as it should be. He favors Colt Frontier .44's.
I'm not sure why anyone would commission Bowen to make a .44-40 in modern times, when we know the .44 Special is a better revolver ctg. Maybe he had a Winchester .44 and it needed company?
I've long suspected that Sasha Siemel's S&W .44 may have been a .44-40, as he also owned a short Winchester M-92 carbine. He was famous for spearing jaguars, but also shot some.
A photo shows his holster looking as if he probably had a Second Model .44, either .44 Special or .44-40. He just called it a Smith & Wesson .44. BTW, his name doesn't look Portuguese because he emigrated to Brazil from Latvia, after Russia seized Latvia.
His book, "Tigrero" is wonderful to read, if you can locate a copy.
I'm guessing that .44 Special ammo may have been uncommon in Brazil in the 1917-1960's period when he was active. But the .44 Winchester was very popular, and Rossi makes copies of the M-92 even now.
If Ray in Rio sees this, maybe he'll know if .44 Special was ever common in Brazil. I don't think our other Brazilian members still post. ??