On the way here from #1 you might want to collect "St Nicholas’ Church" (GC11RHQ) and "Bolt" (GC50TM0).
On the way to #3 a short diversion will get you to "Mill Micro 46" (GC2KRH7).
"Useless" (GC2HP2G) is also nearby, but a bit awkward to get to from this direction.
You're looking for a well camouflaged 3.5x5.5" clip-top box. There's room for coins and small trackables.