Yep, those are the nozzles. You also have the filters, orings and hats (or covers). I'm pretty sure the older Rons nozzles were marked, but those don't have to be Rons stuff. I switched to Kinsler nozzles and had some Crawford stuff as well.
Anyway, you can pin gauge them, or very carefully slide a very small wire drill down them (probably they are some where between .036-.039 I'd think, unless they were running over 1000 HP) and get the size. Flow...now that's a whole ' other can of worms!!!!!