Control knobs for 7690 Super Chet..???

[Rock Von Penthouse]

Hi! I just Bought a nice and georgeous Super Chet 7690 and i need to know where i can buy a control knobs (actually knob heads) for it?
If you know any links i am very appreciate for that.,,Some advice,please!
and now i mean a ORIGINAL USA Gretsch 7690 -77 and not re-issue..
Thanks,this is really important for me.