Thanks, all, for the insight and speculation. I am entertained!
Spent an hour after work today dry-blocking and working the filler. The body of this car isn't too bad at all; I think I should be done spot-filling after a couple more rounds of sanding. I may need to buy another quart of high-build primer before it's all said and done though.
One of our number PM'd me to warn about filling holes with straight body filler (aka "Bondo") because it shrinks back later and leaves a divot in your paint. I told him I (mostly) am not doing that, but instead coming in from the back of the hole with Kitty Hair and only then smoothing the front with filler.
I said this with some swagger, as if I actually know what I'm doing, and on reflection I feel like that's not really right: I don't know what I'm doing.
So...does anyone here have any knowledge and/or experience that debunks my stated method? Because I'd rather re-do these now if need be than after color.
The other thing I did today is I ground away a bit of the tail to try to form a subtle "moustache" flatness under the plate light. I'm sure this will be very subtle at best, but as we're copying a French car, I figured the moustache would necessarily be slight anyway.
I'll probably shape it a little bit back here, mostly with the palm sander, and we'll see if it makes any difference. . . .