I know Gauntleys stocked a few Cornell and Diehl blends when Glynn Quelch worked there. No idea if they ever stocked any Pease blends, tho.
If you want any Pease your only options will be the secondary market (you could ask on here) or buy from a US website. I've used Smokingpipes many times and have received good service. You'll have to pay customs & excise duties, tho. This can work out quite expensive. They even tax you on the postage and Royal Mail have an extra £8 handling fee for collecting the taxes.