My fit-up number umpteen - going well.  front to rear location, shock tower location, floor pan location all good.  getting ready to plug weld all the holes from drilling out the previous brake fluid rotted rail.  Once those are plugged I plan to fit in the rail once more and weld it in.  Nice working with such a solid California car - no rust in the pan or any other portions along this mount up.  I would say the most difficult fit area was here where the fire wall meets the floor pan and the new rail - if this is not right no other dimensions will be met. 

Next difficult area was the floor pan - I had to "bring it down 1/4 inch to "meet" the rail.

Another area of note about the rails out there is the width of the new rail is 5 or so mm wider than the old - no issues but close to pedal box.

Comments welcome - I am sure some of you have tried this?  ?

The frame rail is in!   I used weld through primer and my trusty new ESAB 205 TIG/MIG welder.  I am very pleased with the outcome.  More touch up with paint and seam sealer and undercoat but wanted to share the progress.  The fixtures held to a 32nd of an inch!  Factory spec.