Michael, I thought I should warn you about a potential problem you may run into by doing all your empennage fiberglass work at this point. I did a lot of mine, too, while waiting on my wing kit, back when I built my empennage. Here's what I learned, later on, when I mounted the empennage to the fuselage for the first time.
The bottom of the rudder, as it comes in the kit, will most likely need to be trimmed. I spent a lot of time carefully fitting and drilling the fiberglass bottom to the rudder, not knowing this. I assumed that the part, as it comes from Vans, is made to fit. After all, everything else fits to a T. This isn't so! I was shocked, several years later when I mounted the empennage to the fuselage for the first time, to see this. The rudder bottom doesn't fit right!
So now I have to do all that work over again. I would suggest that you put the rudder bottom aside (when you finish your tail light) and wait until your fuselage is finished. You'll save yourself some effort and wasted time.
One other thing I've noticed, after looking at a lot of RV's at fly-ins and out on the ramp at different airports, is the fit of the rudder bottom. The trim on the rudder bottom should be tapered, so that the final fit of the rudder bottom follows smoothly from the bottom of the fuse to the tip of the rudder. I've seen many, many of them, where the aft end of the rudder angles upwards too sharply because it shouldn't be trimmed at the aft end as much (if any) as it needs to be trimmed at the forward end. A tapered trim, if that makes sense. I don't have a picture to help here, but I hope that makes sense.
Speaking of tail lights, I made a similar mistake. I bought an expensive Whelen tail light/strobe, thinking I would like to just get it done now. This was before LED lights came out. Recently I sold my brand new, never used Whelen tail light at a loss, because I'm going with modern LED lights instead. I know you just bought your light and that's fine. My point is, you never know what might come out in the near future, before you are ready for final assembly of your airplane. Maybe we'll see a big price drop, like we're all waiting for. When it comes to anything electrical or to do with your panel, it's best to wait until the last minute before you jump in.