I don't know if I should say anything or not. I don't mean to bash you in any way.
I've seen some March brackets that were a bit "shakey", or not as strong as they should be. I don't like they're use of what looks like potmetal tubes and long bolts to extend a bracket from a solid mount. Puts a lot of lateral stress on the bolts and the threads they screw into.
I don't see any kind of brace on the rear of your alternator. Personally I wouldn't trust the March bracket to take the load by itself.
I'm not trying to knock your idea. I just thought I'd mention my observations before you went to alot of trouble/money for naught. If its just a show car it probably be ok.
Don't mean to offend you.
Just trying to help.