Why not a Single Shot?

[Huvius]

I have no idea about brass availability for the 500NE but it sure has been difficult (and expensive) to find 50-90 brass lately.

I use Starline 50-90 Sharps brass to make my 500/450 No.2 Musket and I suppose I will for 461 Gibbs No.1 when I get on that project.
It is on backorder now but quite reasonable in price when available.

I love your No.1!
The recessed safety is an especially well thought out modification.
Your cartridge choice is great too. I have one in 50-110 but the Sharps has even more capacity than the Winchester - strangely.
One can load either to easily match the performance of the 500NE as originally loaded which is no slouch as we know.

I've been following this discussion for some time. Unfortunately, I have plenty of single shot rifles - even in DG chamberings - but have no hunting stories to tell of them.
That said, I was getting close to booking a Buffalo hunt in Mozambique and the PH had no reservations at all about backing up a client with a single shot. Of course, my 500NE would have most likely gone but I would be over the moon to take a Cape Buffalo with one of my Gibbs Farquharsons. 461 No.2 or 450 No.1 Express.
That's about as classic as it gets in my mind.