If you get stuck having to use the EMGO keyswitch for your CB750, take a look at the "Keyswitch Saver" relay kits I have on my website (in the signature, below). It has the details about why this is important, and needed.
If you buy from there, be sure to let me know you're from SOHC4.net, too. Members get a little bit of a discount, and $1 from each member-purchase goes back here to support the Forum.