Front frame rails / battery tray, etc. / proper overspray

[68RRFlyer]

So today's the final spray of UU1 on my coworker's 68 Charger R/T.   I've already jambed the car and today is the final body coat.  I'm trying to be correct in the paint as much as I can.   My question concerns the front frame rails being painted on the bottom side, the battery tray and bolts, and the fender tag.   I did the engine bay and kept the front frame rail bottoms primered with some light overspray.  I didn't paint them totally with color.  Is this correct?  I know about how the firewall tunnel, rockers, and the like go with overspray, but the front rails I thought reading somewhere were left primered on the underside and they were not fully paint.  Thoughts?

Also, I painted the battery tray off the car and assembled since from some research I've found, that's how they were done (I think?).  That leaves the bolts that hold it to the bottom and the inner fender unpainted.  Are they or aren't they painted bodycolor?  I was going to shoot them off the car so they match but wasn't sure if I should install the tray then paint the bolts or are they left unpainted?

Lastly, the fender tag.  I painted that off the car too.  Here's the thing; I've read a few different things on painting of fender tags: one is they were hung by a wire and just lighty painted then put on the car, and the other is they were fastened down by one screw (the left one) and bent up a little to get the paint underneath.  I'm thinking the earlier is used for cars in 1970 and later, but not positive.  Dan's tag is bent up a little under the left screw.  Which tells me that's how his was painted; on the car and bent up a little.  His car has a repaint at one point, so the inner fenders were painted when they did the top of the fenders so overspray got on the screws.  So if that's the right technique to paint the tag, is the left screw painted and the right one left natural?

Thanks for the help gang.  All this work and it's not even my car.  But no kids, so maybe he'll leave it in his will to me! 

Cheers         

[gtx6970]

Remember, these cars were painted by human hands, so there is going to be variations to an extent .

battery tray and all it's related hardware are body color.
frame rail color and extent of how much was painted will probably vary from car to car to some degree, and to a certain extent. same goes for how much coverage is on the battery tray as well

as an example , the bottom of the ft rails on my challenger were blue ,but just very light thin coverage. Yet the bottom of the radiator support was almost all primer showing.

it was WELL covered in B5 when I sold it though