The headtube on a Changa is 4-5/8" so you'll want a fork steertube around 6"
As Glen said your options are slim, Redline Proline sound feasible or possibly Champion
How about getting Voris to repop a set for you, gotta be a better option then 'cut n shut'
have you got a frame? Or you gonna have a pop at Ray's 83
(wouldn't mind that myself)