I ran across a write up on using a Ford pick up steering box for cowl steering recently, can't for the life of me remember where it was. Did a bit poking around, and boxes from mid 60's to later 70's may work out. There are some steering box changes during that period, but it's a similar deal on most of them. They can be a lot larger than most boxes, but the sector shaft is nice and long so the steering wheel can be centered without a sector shaft extention. And there is a huge mounting base that could be used with a internal frame work, and not have to count on the cowl to support the box and stress and strain that can be imposed on just the sheet metal. The biggest hurtle will be available space. Still fairly common and inexpensive to get. Had some pictures, but can't seem to get them to post. I'll see if I can get them on here later.