Source for vintage Vox amp parts?

Dodge

Having recently picked up an old AC30, I'd like to replace the missing / incorrect parts - preferably with vintage replacements where possible.  Obviously I'll buy new if I have to.

Does anyone have any recommendations as to where I might find some?  I'm particularly interested in the following:

2 x chickenhead knobs
4 x 1 pin corners
8 x brass strap screws and nuts
3 x back panel screws and cup washers