The answer you seek depends on what you want to use the plans for. If you want to built spot-on accurate repros, then they aren't that accurate. If you want to build cabinets that most people couldn't tell weren't original, then they are as javeryh says -- probably accurate enough.
The widebody plans have been reported as wrong with speculation being that they are just the standard with 4 inches of extra width. I can't seem to find reference to the thread in question, but I do recall the OP being rather ticked as he had already built the cab and none of the parts he had ordered fit (so I would definitely follow sk8er's advice above).