Bit of an update. The BB tool arrived this morning, took the chorus off and fitted an athena sealed unit. I was going to fit the old chorus cup/cone but because I've got a slotted BB, and I don't have the tool for it either.
Anyway it was an easy swap and I now have maybe 7/8mm of clearance. I also took the opportunity to switch over to a chorus crank set I had which is 170 instead of the 175 I had on there, with slightly smaller rings.
Upshot of that is that along with the wider spread of the cranks, the toe overlap is much less severe.
Very happy basically, the more I ride it and work on the bike the more I lean and the happier I am with the ride