Well done ! Love the DIY correction stuff.
Next, adding centered stems to 6u spacebars 
No center stem? No problem 
https://imgur.com/a/xGc3oAZ
- Get Epoxy glue
- Sacrifice a stem from a keycap by cutting it with a nail clipper/whatever. (I used some grab bag DCS keys)
- Place a dab of epoxy and place the stem inside. Wait for it to harden a bit but still be maleable.
- Place the keycap/spacebar on the switch + stabs while the epoxy is not completely hardened and make sure the key sits proper/goes down ok and let it cool/harden.
Tip: practice makes perfect, if it doesn’t go well in the first try, just push on the stem and peel together with the epoxy, clean the stem and repeat.
This also works if you wanna make OG stepped caps lock to be centered stem, but it’s more difficult, and you have to use a shorter stem, and also work an encline for the keycap to sit at the same angle/height with the rest of the row.
Cheers!