I have too been looking . Currently have the Godzilla Fx1 . ID is 63mm.
I 've looked at Power Flow canisters . But they won't sell over the counter . Found a place out in Montague gardens . PRO VAMP . They can make up anything you want . Mild steel or stainless . I asked for a can about 220mm wide with a tip of about 150mm. Stainless = R2500 est.
Mild steel under 1K .
Other option is to chop the FX and insert 76mm.
True Power is Knowing that you can , But you Don't ....
Found a stainless steel box nice fat one... am busy high polishing it and will then fit. also found a really nice 120mm round tip. will post some pics when done...