You'll also want to grab the Rear Backing plates off of the donor Car. That will allow you to use the later 3/4" Wheel Cylinders, and will allow the EBrake Rods as well as the EBrake Swivel/Balancing rod to bolt right up. Later brakes are easier to keep adjusted. You'll want the stronger axles from the Donor Car, mark them and make sure Left Axle goes in the Left Side on the Mk I.
You will need a new 3/4" Master as the Master on the Donor car is a dual line and won't fit the Master Cylinder opening without Surgery. If it is original to the car likely crap with rusty bores. Brake and CLutch piston rods from the Mk I are different lengths from the donor. Use the rods that came on the Mk 1. Examine closely the Wishbones, likely they are cracked and trashed. Check how much play is in the front end, Page 45 of the Moss Manual, Swivel pins may need to be rebushed and reamed to fit. It's worth the effort. And while you are at it replace the Shocks with an exchange from Peter Caldwell at World Wide Imports in Madison WI.Its a while it's apart... New Pads, New Brake Line Flex hosed Front and Rear. Replace rear wheel cylinders, Rear Shocks and all bushings back there as well. Radius Rod gets a lot of wear and tear. Pay attention to the shim on the Radius Arms. Goes on the inside IIRC. Not sure what Rear End a '70 has, think it may stil have a 4.22. there is a Casting mark on top / tab of the rearend two numbers separated by a /. Divide those numbers and it will tell you if it is a 4.22 or 3.9 rear end.