The dual mc is a good idea. I would replace those fifty year old brake lines as well. You can buy prebent lines from vendors or bend your own with a few tools. On the fifty, the front line goes up into the front crossmember and around. Very difficult to install without removing a bunch of stuff. An alternate route can be used here. The split system and dual mc are best put in while you re do the brake lines.
If you buy the bracket for the mc, it would be best to get the mc from the same vendor, to insure that it will fit. There can be clearance issues in some cases. There is a lot of stuff here on this. If you need more help don't hesitate to ask.
