Buy new one here:
http://www.rusmilitary.com/html/airgun_mp654K.htm
SH one should be less.
New ones are still all steel, only the slide is manufactured differently. Change happened about 6-8 years ago.
Old style or new style, it still needs polishing of trigger parts to feel right.
German ones and a lot of SH ones are with low power valves, beware.
Ayosha