Pablo (and Rick),
The guide is of course a Dynamic 658, and as Paul E. points out, my research pegs the availability date at September 1966. Close enough for races 5 and 6, but before that is kinda pushing it.
The front wheels look a lot like Dynamic 601, which would be just fine.
The rear wheels are American Line 1076C (sold by PM and others). I don't think they're really a period piece, but they are the right size and shape, so I've got no problem with them at all.
The bracket is at an odd angle in the photo but looks like a Russkit 795, nothing is more OK than that.
The gear... A Cox gear is a Cox gear is a Cox gear. Original ones had no ribs on the back, later ones (beginning in 1967 I think) had the ribs. Older Cox gears (without the ribs) are rather hard to find, and the unused ones you do find are generally wobbly (nobody wanted the wobbly ones so they didn't get used... and that's why you can occasionally find them now). Wobbly gears make great static displays, but we want to see these builds move, right?
So, I'm hoping we can all get past this business of straining at gnats and swallowing camels, and just enjoy building and running our cars. If the gear is dyed black and says "Parma" on it, it's not a Cox gear, nor is it period-correct and is not appropriate. If it says "Cox" on it, has ribs on the back and runs true, it's still a Cox gear and I personally have no problem with using it. Simple.
There are of course other (non Cox) gears that are also appropriate. Check the reference information provided (example: Auto World catalogs).
Whether or not Cox (or any other) gears came with slotted set screws in 1966, if you're foolish enough to use slotted set screws in a race car, you deserve whatever happens to you.
The Motor: The can is of course from a Russkit 27 and dates to sometime in the first half of 1966. Russkit didn't do a lot of advertising for it, so my information comes from a motor review in MC&T, June 1966, page 48. If Joe Lupo says the endbell is a Cox NASCAR, I believe him. Cox NASCSAR motors date from late 1966 to the beginning of 1967.
I have no idea about the arm without being able to see it clearly. If it's wound on a thick lamination stack with 29 or 30 gauge wire and has a Mabuchi or Tradeship (French) comm, it's probably close enough. If that puppy is wound with 28 gauge wire, it's most appropriate for later races (5 or 6). If the wire is heavier than 28 gauge, it's not appropriate for 1966 at all. Check the Tech Charts.
Hope this helps! It's past my bed time boys and girls. Goodnight.