That is a fine looking gun!
I have both of my NewEnglanders in synthetic (1 black & 1 camo) stocks because the synthetic will take some abuse, but I have a walnut stock buried somewhere in my storage pile.
I would start off with a load of 70 grains volume powder (I use ffg Goex), 2 card wads, 70 grains volume shot, 1 card wad.
My gun likes a little more shot (by volume) than powder and I load 10 grains more (by volume) of shot than powder. (eg. - 70 gr vol powder, 2 card wads, 80 gr vol shot, 1 card wad.) Every gun has it's own personality, and you'll have to do all that boring old experimenting to find out what yours likes.
The heaviest load T/C recommends is 100 gr vol powder & shot!
70 gr shot = 1 oz
80 gr shot = 1 1/8 oz
90 gr shot = 1 1/4 oz
100 gr shot = 1 3/8 oz
I use choke tubes marketed to fit Winchester-Weatherby-Mossberg in my gun, and have had no problems.
As I said before, I have experimented with many combinations of wads for good patterns. Everything from 1 pc plastic wads to T/Cs felt wads, and the best patterns I can get are with the card wads I cut from cardboard (the thickness of the old cardboard milk cartons). I've used (and sometimes still use) a wad of "tow" (flax fiber) that has been lightly coated with a bore butter equivalent I make with beeswax & neetsfoot oil. I tamp it down between the over powder card wads & the shot. It doesn't help patterns much, if any, but it does help with keeping fouling down a little - not that fouling with a smoothbore is a big problem anyway.
The only wad I ever had a problem with was some CVA wads I found at the local gun shop. With the CVA wads some patterns were a bit too tight - like 3/4" @ 30 yards! The wad never opened up or came off the shot column!
My barrel likes real black powder with the #11 nipple for ignition. With any of the subs I get hang fires sometimes. I have a 209 conversion nipple to cure that problem, but the black powder is my favorite anyway, so I stick with it.
Have fun, and if you run into problems or have questions I'll answer if I can.