Not to deter you, but someone is already doing this
http://ttr400.com/photo3_7.htmlAnd, you have already identified one of the other stumbling blocks, most guys looking for billet clamps are also looking for custom offsets/widths to fit different front ends. Makes it hard to do more than one set at a time.
The third stumbling block is this;
Total number of 350F/400F's sold - 100,000
Number left on the road - 50,000?
Guys who want to do stock restorations - 49,750
Guys who would love to have custom trees - 250
Guys who are willing to pay for custom trees - 5 - 10
Rick Denoon