The jet sizes are specified in millimeters. EG.#100 = 1 mm in diameter, #120- 1.2mm dia., #38= 0.38 mm dia. etc.
This specifies the hole or jet restriction parameters. This is the part that does the work.
I've seen (and reused) CB550 main jets pretty knarled up on the outside where someone chewed on it with pliers, or possibly and earth digger. However, as long as the o-ring groove and the inner hole is undamaged, they still work fine. It is very important that the o rings are resilient and seal correctly. Honda still sells these $14-15 per carb. (What price, performance.)
The CB500/550 in it's various models used different mains, #100 (#98 for the F models), different needles (taper profile), Slow jets, #40 (#38 for the F models). There were also different hole sizes in the emulsion tube air bleeds.
Seems like combinations of the stock parts should get you pretty close to tuned. Any aftermarket kits should have different numbers specific to the model type (not just cb550-all). If not, they're just selling you parts, not solutions.
Lastly, if you suspect your needles are worn, consider the needle jets worn, too. I haven't figured out how to renew those, yet.