So what are the 16mm mods?
The little 16mm are my JM16s had the SS one a couple years ago. It was gifted to me and my cousin came to visit and she fell in love with it. It worked really nice with her little cheapo clearo. It really made it look so much better than her little EGO. I let her borrow it indefinitely, but missed.
I had the Piccolo in SS and the matte satin, had a couple GUS's gave some away to family and sold the others.
SInce then I have been missing them. A good buddy here has the hammered brass with a spheroid and have always lusted after that. A few months ago, I found one for sale on FB and then got in contact with Jaceks son on the JM page on FB. He found some parts and his Dad made it up for me.
In the meantime the one on the FB classifieds was not selling and the guy was so nice, he sold it to me for such a good price I ended up getting it. He had the same brass and the SS steel. SO now Im torn between just keeping all of them or keeping the one Jacek made for me and the SS tube and selling the spare brass. I know I dont need 3, but .....
Id love to get another GUS, but if I do I have to give up one of the JM Brass.

I think you will love the GUS16. I kinda liked it better than the Piccolo. Both are gorgeous, but something about the top cap of the Piccolo was hard for me to put together. If I did it wrong Id get a hot switch and have to fiddle with it. I never had a problem with the GUS 16.
Another plus is that the JM, GP and GUS are compatible and you can mix and match the switches and top caps.