Daystate Huntsman

Looks like the Revere, side lever action, came out in mid-2020. I saw a review by Alpha Militaria that was reviewing it in July 2020 that said it was not in stores yet. He is in England so I'm guess it did not "come across the pond" for a few months after this.

I think the addition of a regulator is even more recent. AOA seems to still have some unregulated ones they are selling for less money.
 
AOA seems to still have some unregulated ones they are selling for less money.

FWIW, in my opinion the Daystates (and Brococks) with the Slingshot hammer are almost as desirable as the regulated versions (with or without Slingshot). As I recall the .25 calibers don't use Slingshot, but .25 is the wrong caliber for the (low volume chamber-tube) Revere anyway; they're awesome in .22 and .177.
 
I've seen some impressive shot strings with unregulated reveres in reviews. I really think buying an unregulated one, trying it for awhile, and possibly installing a regulator later is a viable path. You can buy the regulator from Huma and still not spend what they ask for the regulated version. You might decide it doesn't really need a regulator. I think Ed who does the spreadsheets for the 30 yard challenge (thanks Ed) was going to install a regulator on his in 22 because he was a bit tight on shot count for the 30 yard challenge. But if you had a 177 which is tuned to a lower power I don't think you'd have that sort of issue. The 22 would have plenty of shots for a day of hunting.