Please re-hide exactly as you found the cache. There is no need to disturb the dry-stone wall at all. On a recent maintenance visit I found the container had been moved to inside the wall, which required removing some stones and replacing them. Please do not disturb the wall. Thanks.
As far as I can tell, most of the land to the west of the cache is under a CRoW notice, so I think you are free to roam. However it is incumbent upon you to double check your access rights - especially if you intend to bring pets along as sheep are a common sight in the fields. I had a chat with one of the local farmers who didn't think dogs were allowed on the common especially when it's lambing season.
A CRoW access map is available here. (In case that link doesn't work then you should be able to perform a search, and enter the following Easting: 373125 Northing: 463125. Zoom all the way in and you'll see the plantation on the right, and the CrOW area west of it).
If you park up at the indicated location, then you can follow a bridleway that will lead you to a dry stone wall. Follow the wall south and it will take you to the cache. The ground around here can get very boggy at any time of year, so tread carefully, and use common sense.
The plantation to the east and north of this cache was created and planted by my grandfather in the early 1970s, not long after I was born. Over the following 30+ years the trees matured and it turned into an impressive forest. However it was always intended to be a commercial venture, so it couldn't last. Starting around 2004 the forestry company who took over the plantation following the passing of my grandfather began felling the trees. Quite a shock for us that have grown up with the area being quite heavily covered.
Now the land is quite bare, but it seems the forestry company will begin replanting in the not too distant future. Hopefully the next 30 to 40 years will see another forest develop just like the original did.
Update: The replanting is well underway now, with a good variety of trees going in. The original plantation was planted in very strict rows of trees, but the new one is much more random. It should soon start looking like it should do.