Guys,
IMHO, the challenges on this project were mainly
(1) Constant scope creep, which is typical of light restorations where the more you do the more you find needs to be done.
(2) Shop with little to now experience with E9's, and also with
(2a) Seemingly little desire to become E9 experts - Scott had to go find all the info on many many things
(2b) Shop without strong mechanical expertise. In contrast, a shop like VSR1 can do any level of body restoration but Mario also has a top class mechanical shop that can do anything from a belt change to a full-on custom race motor build. This means he has IN-HOUSE expertise at E9's in all areas other than interiors (which he has done by trusted subcontractors). Mario has invested the time and $$$ to become an expert so things get done right and get done efficiently.
Timing: the problem with scope creep is, in my opinion, this.
(1) Shops need to schedule work in advance to keep their employees and shop busy.
(2) When a small project comes in the shop manager will make space in the schedule with a little wiggle room. But other projects will get booked into the schedule around assumptions as to when the simple job will be done.
(3) as the simple job grows and grows, it can screw up their schedule for other booked business.
(4) What sometimes happens is that the project that started simple is now slowing down because other customers with promised start dates have brought in their cars and expect their work to get started. The shop is now spreading more work across their same capacity, meaning everyone's project is going slower.
(5) If the total scope of Scotts project were known from the beginning, I think Mario could have finished it in 2-3 months, done a much higher quality job, and had little to no need for the owner to chase anything down.