I recently repointed our fireplace using Lime mortar. I order 25kg of Lime mortar (unhaired) from this website: http://www.mikewye.co.uk/
They delivered and it cost about £16.
It's a lot of lime mortar, but it comes in a plastic tub and it's stored in water so it should last for quite a few months. I couldn't find any other places that would supply me with less than this.
Just as a counter to the lime putty purists, I'll suggest that you go down to the nearest builders' merchant and buy a bag of hydrated lime. Mix it with sharp sand at a ratio of 3:1 sand to lime, or, if you don' want it looking too white add a bit of earth subsoil into the mix, maybe a shovelfull to the a wheelbarrowfull of mortar. Mix it all very thoroughly while still dry. Then gradually add as little water as is needed to produce a workable mortar.
Mike Wye supply Ecomerchant with their lime(or at least the lime I've had from Ecomerchant was from Mike Wye) but for a more local supplier try http://brickandlimesupplies.com/ based in Maidstone I've no idea where they get theres from but I pressume delivery will be cheaper
Any general reason why you prefer B&Q to Wickes, NT, is is this a personal grudge?
Funny how we don't really know where our lime comes from. In days of yore lime would always come from the nearest outcrop of limestone or chalk because transport costs were humongous. Now that we don't care about oil depletion, global warming, road kill, traffic noise and road building, our lime may come from a very long way away and by a circuitous route via distribution centres. St. Astier is in a foreign land.
One of the bigger lime producers (1.6 million tonnes per year) is Singleton Birch in Lincolnshire. A horse cart ride away from me. They produce some of the best high calcium putty. SPAB are organising a tour round the works in October.
There were 260+ limekilns in Northumberland - mainly for agricultural lime though. If land had a lime outcrop and coal on it the rent more than doubled.
There were some very big kilns which exported lime (Get this Quick lime was exported by sea in wooden barrels - nice!) Probably the most frequently seen are on Holy Island - Lindisfarne where there was plenty of lime and the coal was shipped acroos from the mainland. Even had it's own railway.
The ones at Littlemill had sidings directly off what is now the ECML.
Most of the Northumberland kilns which are still at all complete have been surveyed. Different styles etc but all essentially the same - coal and lime in the top, set fire to it, and shovel quick lime out from the bottom.
Any County with lime had them.
The National Trust (IIRC) restored one in the Lake District to make lime for their property nearby. (talking circa 1983).
That was bought for the Erdigg estate in order that lumps of burnt lime could be crushed to make lime mortar, plaster etc to maintain the many buildings on the estate.