Rare T. Machine guns

Well I am leveling a lv 35 Gu/Ra and my trusty Yasminkovs 2000H aren't putting out as much damage anymore.

There's two T. Machine guns I am really interested in the long run:

Yasminkovs 9000M and Guld Milla. My doubts:

Yasminkovs are listed in Cirnopedia as drops from the rare Rockbear. Is he the only source for them? If not, where did you get yours? Also, my 2000Hs are potential unlocked(lv1), so for the 9000H, is it worth to unlock the whole 3 levels or just one is fine?(don't even want to think about all that grind)

Guld Millas were my holy grail of PSO. Are they as hard to get in here too? And again, is Elder the only source for them?

Yasmin 9ks drop from the rare Rogbelts and certain stages in Extreme Quests. I think they are pretty rare to find, but they are really cheap at this point. Well, if you have premium that is.

Guld Milla drops only from DF Elder. The drop rates for 11* and above are horrendous.