Welcome to the forum, I put square frame target grips on every N-frame revolver I shoot because they fit my big long fingered hands. If you were fortunate to get the original grips it would be in your best interest to keep them if for some reason down the line you wish to part ways with your very nice revolver. A letter would sort out any questions regarding your revolvers history and its trip to the factory.
I just got interested in early hand ejectors with the purchase of a very nicely refinished model of 1937 Brazilian contract revolver. Like you I am very familiar with .44 caliber revolvers and for some reason have never paid any attention to .45acp as a revolver cartridge. Now I have been bitten real hard by the bug and find casting bullets and reloading for the .45 is taking me away from shooting my black powder rifles just a little to the point I am beginning to get guff from my dyed in the wool black powder shooting buddies. I hope you enjoy your HBH revolver, they are truly interesting pieces of history.