Do you have a new style mini starter? You could eliminate the solenoid altogether and use a 30 amp relay to get power to the starter mounted solenoid.
@Mustang5L5 helped me out through that process. I liked it better that having the whole solenoid inside the fender.
For the grounds, I ran one additional wire from the negative terminal into the fender well and attached to a bolt I installed on some clean metal. I attached everything else to that bolt. May be a little different if you’re moving your battery.
Do have a pic of the brake lines under the pinch weld? I’m redoing my brake lines now, and may want to go that route as well!