Has anyone tried Brass cartridge mounting screws?

I use brass/Soundsmith, when I am trying to add weight/mass to a cart/arm combination. Can't really say that I notice a difference sound wise between it, aluminum, plastic or stainless steel which are the other choices provided with the Soundsmith screw sets. Enjoy the music

There are much better (looking) screws to add weight than those from soundsmith. 

Transcendent Frequencies offering them on ebay in different length/weight for any tonearm/cartridge. 

Remember, your cartridge mounting screws must be nonmagnetic! 

P.S. I am not crazy to expect any difference in sound using different screws, they need only to add weight if the headshell is not detachable.

Wow! 

You're certainly a  uh..experimental type of guy.
https://systems.audiogon.com/systems/6601

Effects perhaps not as dramatic compared to your other findings.

Yes, they are cute!  I have no idea where or when I got them.  I just use what I got.

 I just bought a set of screws off ebay from the UK.I notice quite a difference in midrange and bass but I had to put the counter weight back further on the tone arm to compensate for the extra weight so I really don't know if it was the screws.Anyway whatever the case my rig sounds better for less than 20 bucks.