Brisket (but not quite)

A few weeks ago our local supermarket had a sale on "oksetyndsteg", so I bought one. It looked good, and resembled a brisket more or less. I knew it was not a brisket (it's actually a sirloin roast, according to ordbogen.dk), but wondered what would happen if I cooked it like one.
So I tried! First covered it with a mustard slather (yellow mustard, beer, worchestershire, one other ingrediet I can't remember), then a basic barbecue rub. Somewhat resembles this recipe, but seriously, I just kind of do it by feel... and whatever I have:
1/4 cup firmly packed brown sugar
1/4 cup sweet paprika
3 tablespoons black pepper
4 tablespoons sea salt
2 teaspoons garlic powder
2 teaspoons onion powder
2 teaspoon celery seeds
1 teaspoon cayenne pepper.

Got the grill going at 5:30 a.m. - but I always forget how many briquettes to use for this kind of thing and had way too many as usual. I had them off to one side - instead of distributed on two sides of the grill. I've discovered it's easier to keep them going this way.
Put a chunk of alder + a chunk of mirabella plum wood on the coals.

Usually do the briskets on the grate over a drip pan, but this time kept it in the drip pan the whole time, just to see if there was a difference. I've read that it helps keep them more moist if using a Weber grill instead of a smoker.

Temp was supposed to be between 230-250 degrees F, but it was up around 400 the first hour or so.... Argh! Couldn't get it down. Had the bottom vents just barely open.

Started basting with Cola baste (Coke + beef soup (had some homemade soup in the freezer but not pure bouillon!) + ketchup + brown sugar + hot chili flakes) after the first couple hours, every time I opened the grill. The fire went out almost completely around noon, and then I started up just a few more briquettes, but - stupidly - those weren't enough -... so I started a few more. Again, those weren't enough, so then I started a whole bunch and of course it was too many. Kept the chunks of alder or apple or mirabella smoking throughout the day.
Anyway, the thing was getting real tender and smelled incredible by the time dinnertime rolled around, 6 p.m. Brought it in and let it sit for awhile before slicing.


Had it on Anette's homemade buns with slices of raw onion, baked beans and potato salad (Anette used the rest of the mustard slather in the dressing - amazing).
It definitely tasted different than brisket, but it was wonderful. Tender as hell, but.... not quite as sharp in the bite. Don't know how else to describe it. Kind of mushy, actually, in parts.
Anyway, next time: will try to find a real brisket again. Yet another cut of meat (oksespidsbryst) we have yet to really see done properly by Danish butchers!

Leftovers were great, too. The first night, I put the rest of the brisket in two sheets of foil, then poured the rest of the pan juices over it, plus some more of the basting sauce. Just heated up that whole packet real slowly in the oven a few nights later. Yum.