The centre stand should remove with the side stand staying in place with the upper bolt.
Your side stand is welded on, correct?
If you weld on a longer bolt onto the centre stand.........try to get a bolt with a shoulder long enough to go through the frame and your side stand.
Use a 10mm bolt. The stock stud has a 10mm shoulder, but drops to an 8mm stud.
You will need to use a nylock or stover nut with a flat washer as you can not tighten the nut up completely. It needs to swing with the centre stand.
Once you install the nylock/washer, cut the excess bolt off.
HP2 Sport, R1200S, R100S, KTM 640 Adventure, KTM 520 EXC/Motard, Yamaha RZ350, Hodaka 125 Wombat