Dear Mumzie... If I was you, I would get me a few different balls. I just recently switched to Storm, but I was throwing LM equipment. LM equipment are a very unique type of ball reaction vs all the other companys. They Kinda stand out like Mo Rich does compared to Storm... Just take a look at some of the reviews of the LM bowling balls and see what they say.
Most every review you will read will be something good towards the ball. Not every Manufactory can have reviews like this. The two main things people like about a ball such as LM is Longevity and Pin Carry! Its just obvious if you take the time to read what the people say. Visionary is the same way. When people talk, they talk mainly about how good these "two" aspects are in these bowling balls.
The thing that makes LM balls stand out is most of their balls have really high RG's. I have some friends that know they shouldnt buy a LM because they will tend to shoot the ball through the breakpoint. This being said, with your slower ball speed this may be something that you really need to try. I would suggest you getting a Terminator drilled with the pin 5" or more from you Pin to Pap. This ball will probably rank up there in being as strong as the Domination but it may have a better carry%. You can find these balls right now at a very good price so it isnt like you will pay 270$ trying to get into one of these things.
I realize you may not like what I had to say and thats quiet ok. I just wated to help in any way. Looks like you are already a pretty advanced player so I dont think it would take anything to get that pain to go away from your shoulder. In the back of your mind you probably already know what to do that would help it and maybe dont want to try, I dont know. One thing tha may even help is to go a little more Forward with your thumb pitch. This way you can completely free up your armswing. I have tried many different pitches and have found 1/2" and 5/8" Forward is what most people need to be at to find a "ZERO" GRIP PRESSURE. Only the most advanced bowlers can accomplish this kind of pitch in a short time. I was at around 1/2" Reverse and now I am at 1/2" Forward. And since I wasnt as most as advanced as some people, it took me quiet a while to finally get comfortable with it. The good thing is that you are already going the right direction with your thumb you just maybe need to keep going until you cant. I would bet anything that if you have a relaxed span you cant swing the ball back with no grip pressure and not drop it... Sure you can half way do this and keep it on your hand, but I am talking about holding the ball like a new born baby. 98% of people that try this, will in fact drop their bowling ball backwards. Very Very Few people, can say in this world that they have zero grip pressure. At times I still feel I may have a little, but most of the time I dont.
My points in telling you this is because I recently switched to storm and my carry isnt near as good. I have only been throwing storm for 4-5 days now, so it may get better once I learn the roll of the balls a little better. Most people would say thats BS but its obvious in my game... Also, the reason I said so much about Forward pitch is because if you can get a zero grip pressure, your ball speed will automatically come up. 95% of the Bowling world doesnt have the proper ball fit, and if you feel your ball is perfect then disregard what I have had to say. If you have a free armswing then in most cases your revs will be balanced with your speed. People that find they are rev "dominate" are players that do some grabbing, jerking, or anything other than just being smooth and letting gravity do all the work. But anyways, sorry this was so long. Hope you liked what I had to say. John