At Bow Lane Record Office in Preston. It is possible it went through the Richmond court but it would still be at Bow lane, if it wasn't Richmond it would be chester.
unless he didn't have a will and letters of administration were applied for, even they would be in bow lane, this is because prior to 1858 the diocese were responsible for wills and bow lane record office in preston is now the diocesan record office as well.
I think you can check for it online hang on,
http://www.lancashire...4528&pageid=30539&e=e
also, the Lancashire Parish register society or the antiquarian society have indexed the wills 40 odd years ago and published the index which should be available in any lancashire reference library.