The written was pretty simple. Personally I dont think it warrants buying any pricey books. It is common use stuff that deals with instrument procedures and what not.

I was instructing back then and as CFII and MEI it was for the most part stuff I taught students on a reg basis. If you are a 135 pilot or something like that a lot of the stuff the written covers may have slipped out of your mind.

Just my 2 cents.