Funnily enough I brewed this yesterday. I used a recipe similar to that posted by Terrym so likely the same source. My mash temp was a bit off (64 degrees) and I went with a 60 minute boil. I couldn't get hold of the sussex 1 yeast so went with Ringwood ale yeast. Its fermenting away nicely.
This is my next brew as Harveys Best is definitely in my top-10 and plan to use the same recipe as above this time as an experiment (I tried a similar recipe last Christmas and chose not to use the Maize as that didn't sound very authentic and the result compared well with Harveys from a 5L tin). I used Mangrove Jack - Liberty Bell Ale M36 which I read somewhere on tinternet gave nice fruity flavours. Was pleased with the result although not the same as a freshly poured pint in Sussex.
LH - From the Harveys shop.
RH - My attempt.