Raston, looking at your pictures I see that now. Good job as I had not noticed the "plug" before.
This is how I did it on my Christen Eagle so I guess good minds think alike
However I have seen pictures of some peoples planes and no plug is visible. I have to assume they desoldered the cap or something.
On my new GP giant stik I was lucky that it had a hatch plate on the bottom so all I had to do was cut a notch in the end of the plate to run the spark plug wire.
Had it not had this plate there was not a whole lot of space to drill a giant hole in the fire wall for the cap to fit through!
BTW, my Roto 25 is on this stik for now until I finish the spitfire. The 25 will come off the stik and be replaced by a 35.
The 25 fly’s this stik really well but it could really use a 35 for all out performance.
Bob
Pictures of my stik below