Found crawling up a gravestone(!?)
No interactions present.
Looks very similar to a caterpillar I found in 2012 that I thought was this species. Take a look at http://www.ispotnature.org/node/270989 and see what you think.
I'm not confident of my ID (and have not had any agreements) so cannot agree with your ID above (although I suspect you are right).
It does look very similar, i think they are at least the same caterpillar.
Lat/Lng: 52.9569325, -1.1584761
OS grid ref: SK566402