Now that I re-read the first post I see OP's mention of the solenoid downtube. I had the steam wand in mind when I was trying to say it's rather normal to see a little water come out. Oops. Now I understand why the last few posts were written - wondered why on earth we were going down that path.
I think the variable that is being described is the least of amount of fines, ie the cast burrs have much less fines rather than much more fines. The reason I'm saying this is that the one listed second is the low fines version, so why would a burr named low fines have more fines than the other two (high uniformity and low uniformity)?
I didn't kno Cerini had a harness, thanks! Yes boiler may have pin holes. Joe gloe the cap, most boiler smells I had came from the inside top of the cap or top of the boiler. Good luck, sounds like you are all set.