RD400

No.

My guess is that enthusiastically ridden RDs (and that's the way to ride
them) went down on the left more than the right, because that's the side
where the sidestand and centre stands dig in.

 

Incorrect.

The centrestand protects the left silencer when they go down the road
on that side. The right silencer has nothing to keep it from sliding on
tarmac - hence good condition right silencers, be they used or new, are
harder to source. Also, an enthusiastically ridden RD will lean as far
as the silencer will allow on the right side, and centre stand on the
left. I've owned a couple of RDs that I know for a fact have never been
dropped that had huge scrape marks on the underside of the right
silencer - one of them I bought off my eldest sister with only 800
miles on the clock - it was me who scraped the silencer.