Vintage wallpaper discovered

I live in a croft on a Scottish Estate in Aberdeenshire, not sure how old the building is, but I have done some research and so far found out it is at least 151 years old. The part of the house that is my kitchen, originally wasn't even attached to the main part of the house, I think it was an outbuilding. There was also a lot more out buildings than we have now, with one of them being a Smithy's which was situated in the corner of our garden. I'm curious to find out more so will be doing some more research.

We've been having some problems with damp on the back wall of the croft, even though there is a path and a small retaining wall as the ground is higher than the building. The Estate have put in a field drain along the garden but it is debatable as to if this is working how it should. The joiner has also been and taken down the back walls to the bare stone and replaced them with plasterboard and insulation.... yay insulation.

The downstairs bedroom had old lath and plaster, which really was in need of being replaced. I found it interesting to see the bare stone walls, I wonder if this is how the first tenants saw the inside of the croft or did it have lath and plaster walls?

The other room to be done was my art/computer/dining room (which was recently decorated!). In this room the joiner found that it was plasterboard on the wall and shouted me through to see the old wallpaper that was on the wall underneath. This stone wall had been plastered straight onto the stone and then wallpapered. 

Here's a couple of close up images of the wallpaper. I wonder how old it is?  Who put it up?  Who lived in the croft at the time? The colours are quite bright, but faded in some places. I love it. The joiner (whose name is Steve) managed to peel a couple of bits off for me and I think I might frame them and hang them back on the wall after it's been decorated.

FACT: plasterboard didn't start to be used until the1930's, but this doesn't mean that the paper is earlier than the 1930's because things don't happen fast around here and the plasterboard might not have been put up till 1960's or 70's.

When I took the close up photos I noticed that there was another layer of paper starting to peel away from the pieces I had. I'm not liking the wallpaper as much, but I would love to know the answers to all my previous questions about this paper too.

We now have two rooms with lovely insulated plasterboard walls which can now get decorated. I'm especially pleased the bedroom is at last going to get done because once it's finished we'll have somewhere for visitors to stay.

I'm happy about my new walls and the Estate are going to be looking into where the water is coming from that causes the damp and how they are going to deal with it, so hopefully it is dealt with fairly soon.

If anyone has any idea about the date of the wallpaper please leave a comment and I am going to do some more research as I'd like to find out as much as I can about the croft.