Chris, it would seem that your summary is correct regarding Blackpool and Preston. I suppose Blackpool is slightly out on a limb but you would have thought Preston (now a city) was big enough to warrant being the base for some decent girls. We have no agencies to speak of, though a couple of seemingly fake companies appear in searches.
Personally I don't like parlours so for me the likes of VIP and the various locations of Lancs Massage (Abba's, Barrons etc) are no good and every time I see a new face pop up on AW in this area they turn out to be rubbish!
It's a sad state of affairs but I suppose, even though we have a group of us punters over here in the PR and FY postcodes who would relish some quality service, there must be more work for them all over in Manchester.
We just need one or two attractive girls who provide a consistently good service and they would make a good living. Its certainly an untapped area for the right minded WG to locate.