I ended up lettering this with the old livery and I changed it to #66.
It still needs some work and maybe some day in the future I'll change it to the speed lettering. I chose this more subdued decoration because I feel it fits better with this engine. I got a new boiler plate from doityourselfletrering.com and customized the boxcars as well from 742 to 734 and 718 respectively.
I have an unaltered version of this boxcar as well but it's stuck in storage 2,000 miles away.