Chicago seems to be working ok for C , but I can't find a single date between 7/8 and 30/9 when either the PE or C offer comes up for LAS.

Fares seem to be unpublished, so not on EF - but for ORD you can get GBP 970 return as long as there is availbility in the J bucket and you stay a Sat night.

The PE fare doesn't seem to work for either.

Added - if you use the link (but not the main page) you can actually select a business restricted fare ex-LHR for only 30 quid more than the ex-MAN fare. That's a first! You have never been able to price up a J fare ex-LHR on the website before for one of the MAN flights. Hope they do that for LAS as well if/when it starts working.