Todd, a few comments that might help.
Plumbing: you can get the brass fittings at Autozone in bubble packs. They are all "inverted flare" type, male, female, 3/16" and 1/4". I posted PN's in prior posts (search). Insure you install a flare adapter in the 1/4" top junction block port. Do not direct plumb a 3/16 tube to it or it will leak. Plug the port where the rear tube connected. You could also plug the 1/4" port and run the front MC tube to the 3/16" side port (formerly rears), though less elegant.
MC:
The 1968 MC is cast-iron and those tend to have leaky tops. An alternate is a later aluminum MC. You can get a 2 to 4 bolt adapter ($30 ebay) to install one. Dr Diff sells MC w/ plate for ~$100. Many here use an MC for a ~1985 Dodge truck. I used one for a 95-99 Breeze in my 1964 Valiant (see post) and the brake pedal wound up in the same place. Insure you have a rubber bushing to lock the tip of the brake rod into the MC piston. Unbolt the brake lamp switch until finished, then adjust it to sense the pedal.
