Here is the final recipe I settled on, I've used less base malt then my previous attempt& have added 150g of Chocolate Malt. I used a similar hop schedule as last time, but used Challanger & Styrian Goldings as I had them lying around from a previous brew.
4kg Golden Promise
350g Crystal Malt
300g Roasted Barley
150g Chocolate Malt
150g Special B Malt
30g Challenger 60mins
26g Challenger 20mins
16g Styrian Goldings 10mins
O.G = 1.044
Brew day went OK. The tap on the boiler was open when I started sparging, I lost a couple of pints on the floor before I realised.

I almost electrocuted myself & blew the boiler because of this......
oh well, it all adds to the fun!
Its currently in the primary fermenting away nicely.