3-pin regulator

Great!

 Thank you very much Barry!

The point of it being bolted to the frame was to use the frame as a heatsink.  I would mount it like the factory does with a set of insulating washers and a mica insulating washer.  The TO-220 package doesn't dissipate much heat in open air, drawing more than 100-150ma through the regulator in open air it gets pretty warm.

In light of John's comment, I've removed my previous post.

Although I've run PS2 5 volt boards for extended periods of time on a PS2 test fixture without grounding the voltage regulator and had no ill effects, I'd also use the tender chassis as a heat sink,

Barry, I've run them with the regulator in free air when testing, but the regulator does get warm.  I figure why take a chance.   What will happen if it gets too hot it it'll go into thermal shutdown and the 5V will disappear.  That will correct itself when it cools down.

Do as John stated with the insulating washer and mica.  If the metal on that reg touches ground, you will blow the board.  After installing it where it is going to be, to check your proper placement of the washer and mica by doing the following.  Get your meter out and set it to continuity and touch one probe to ground and the other to the metal on the reg.  If you get continuity take things apart and reinstall the washer and mica until you have no continuity with ground.