Need replacement balances
Greetings! To respond to your first set of photos, it looks to be our Series 380 balance, but it could be our Series 385. To determine, you'll need to measure the depth of the plastic balance shoe. If the shoe measures 1'' you'll need an S380-31 balance. If it's 1-3/32'' deep, you'll need our S385-31 balance. In both cases, you will choose the 3030 option, since your channel is stamped "30 3."
And for your second round of photos, the plates you refer to are known as top sash guides. Without seeing them out of the window, we can't be certain which will work for you, but I think they could be our 18-124P guides. If you're able to remove them from the window, give them a comparison and let us know what you think!
You are probably correct with the top sash guides also. I have attached pictures for your viewing enjoyment.
I agree, I think you selected the correct parts for your Rollyson window. The only other thing you might need is a 16-002 take out clip, but only if your current ones are broken.