Question on Beef Shoulder Roast Substitution

I have a recipe that calls for a 2lb Beef Shoulder Roast.
I have been 4 different places and cannot find one.

What cut is this similar too? Does anyone have a recommendation on a substitute, Chuck Roast maybe?
This will be a slow braised cook for 2-3 hours.

Cook's Thesaurus suggests bottom round as one subsitution.

Boneless cuts from the chuck or round should work, e.g. boneless chuck arm pot roast, rump roast, bottom round roast.

Pot roasts

Beef cuts chart

Maybe two years ago, I purchased a beef roast at Costco and made a pot roast. I really didn't like it. It just wouldn't get tender. I made the mistake of purchasing it again last year. Horrible. I actually took some of the pieces and put them in the oven for eight additional hours, just to see what would happen. The meat disintegrated, yet is was still stringy and chewy.

I only make post roast once a winter, but I've been making this since I was about 8 years old and haven't had failures until the last two years. Yet, now I was failing terribly. I was stumped. I was sure it wasn't my method, as that was tried and true, so that left me the cut of meat.

I went to my favorite place when stumped by a cooking/baking problem: Cook's Illustrated. I don't always agree with them, but they give me enough information for me to decide. In this case, they'd tried many varieties of chuck roasts and determined which ones worked...and which didn't.

Turns out the the roast I bought at Costco was one they labeled as chewy; tasters indicated that it was stringy and was like chewing cud (OK, maybe my words, but...). Exactly what happened to me!

I took their suggestion for my next roast and bought a 7 bone, as that was what I easily found. Bingo! It was exactly what I wanted.

I still go back to that CI chart to see which parts they recommend when I need a beef roast to braise. Their list for top for flavor and tenderness are the chuck eye, a 7-bone, and a top blade. I just looked and couldn't find the original chart (they've a site makeover and I'm missing some things I've used for a few years!).

Now, not sure what you're using this for, so it's possible that this won't help you. But, hopefully it will.