The Travelall axle should be wider by a few inches.
I have specific experience with a 69-73, but I think the earlier (from 61?) were pretty much the same..
The Travelall uses 2.5" wide springs vs. the 2" Scout II springs.
My understanding is the T'all front perches are the same width as a '73-87 Chevy pickup. I KNOW that the Chevy pickup (a 1974 version in my case) will bolt right into a Scout II without moving the perches or springs. I just had to do some grinding on the sides of the perches so my U-bolts would sit flush against the narrower springs.
I would expect the T'all front end to be no different.
The rear end has the perches spaced wider apart. I had to move the perches inboard when I put a T'all rear '44 under my Scout II SOA style. I also had to do some grinding to them, again, to sit the U-bolts against my 2" wide springs.
Earlier D44s may use the small U-joints.
The truck/T'all D44s also used 19-spline long stub-shafts and internal style hubs - so the SII external hubs won't bolt up.
You'll need some steering linkage stuff done, too. I chose to retain the stock tie-rod and used a cross-over steering setup with a custom GryphinRacing.com draglink.
If it's an open knuckle front axle, you could swap the SII knuckles, stub-shafts (if the '44 uses big-joints, use SII D44 stubs. If it's a small-joint '44, use SII D30 stub shafts), hubs, rotors, etc. This will void any chance of doing a cross-over steering setup, and you'll need a "Z" draglink (custom length) from GryphinRacing instead. You might get away with re-using the stock T'all tie-rod with the SII knuckles.
published an article on converting an early 70s Travelall 4x4 to disc brakes a while ago - reprints are available. They used F150 hubs, with modified SII rotors, Chevy caliper brackets and calipers.
The problem is the Travelall used a 6-bolt spindle while the SII used an 8-bolt setup, so your disc stuff won't swap straight across as easily ad you might hope.