The bike was indeed fitted with a centre stand when I bought it. It also has lugs at the rear for a main stand (one of which is broken)as well. I'm in the process of re-fitting the rear stand and don't plan to replace the centre stand.
Additionally, for a centre stand to be used with these plates they will require bolstering in the area where the stand bolt is fitted.
The plate thickness I have used is 5mm, the originals appear to be 3/16", it doesn't really cause too much of a problem for me as I'll be making new spacers to suit - the bike had some bits of plastic pipes fitted as spacers when I bought it, believe it or not :astonished: