Newbies Fox and partner, though not quite rare is worth a lot of money. You know where to start.
The cache is not at the listed co-ordinates, but is in the vicinity of…
North (two revolutions to the Solway Fisheries) (The Bank of England) . (Imperial taxes, Dottyville Lunatic asylum, The Midland Railway)
East (Three Acre Cow Farm) (One revolution to the Midland Railway) . (Solway Fisheries, Tareham Steam Laundry, the length of the battle minus 5)
To solve this cache you need to expand on knowledge gained from solving DD1 & DD2.
You can check your answers for this puzzle on GeoChecker.com.