Oh wow! I wasn’t aware of the 501. I like it’s look. Definitely fits in with the other “automatics.”
Wonderful collection! The Uni drafting series has quite a number of great models. My favorites are right in the middle, those 3 brushed steel ones with stamped accents in 0.3 mm, 0.5 mm, and a 2.0 holder.
When was the last time you saw a Uni all steel holder on the marketplaces? Seems like it has been over a year.
There is also the plastic AUTOMATIC 303 but I have them on another tray, and it’s still too messy…
I remember you were still searching for the 2mm SUPER lead holder… and yeah, it hasn’t shown up much. But then again, once a model is crossed off my list, it kind of dips below my radar? Will definitely buzz you if I spot one 
I just noticed the clips are different between the 501s at the top and the ones at the bottom. 
I definitely prefer the top ones.
That is very beautiful!!
Wow! If you ever decide to part with the yellow one (third from the right), please think of me 
I actually DID pick one up, back in early 2025. I paid a little over the going market value that had been trending then, but ones that followed were about the same, or even higher, so I didn’t do too badly. And in fact, it’s in pristine condition just no price sticker (clip isn’t scratched or suffering from chrome plate bubbling), and it even has the original Mitsubishi lead in it, with the little blue retainer piece at the back end. I wonder how common those are these days?