Looks similar to one I have. My old man picked it up for a tenner at a bike meet a few years ago. Makers mark was in one end, first owners mark in teh other. The blade may also have a makers mark on it, and if that matches the body, you have a reasonable set.
Make sure the wedge comes free and have a look at the business end of the iron. Also, check that it has a cap iron. Checking the sole for flat and fixing it is easy enough.
If you get on well with the landlord, just ask him if you can borrow it for a weekend, to give you a chance to clean it up and examine it. If it looks viable, offer to make him something with it to take it’s place on the shelf.
There is a vid on this from Paul, but I don’t remember if it is on WWMC, or on youtube.

The important parts are missing in the photos….. the sole and the Iron, so it’s impossible to say how much life is in that plane. It would probably work if you could warrant the time needed.
As Sven said, older wooden planes are often well-worn by the time that we get hold of them and the mouths are sometimes too wide for accurate work due to the sole being planed and flattened many times over their working lives. The answer was usually to ‘re-mouth’ the plane. This involved cutting a section out of the sole in front of the mouth and inlaying a new section of wood, allowing a new, closed mouth section to be made. If you can do this, fine, the world’s full of old planes, but it does need accurate cutting skills.

The Japanese had a different solution to sole maintenance, but that’s for another day.

I also have a Clifton No 7 that’s even older…. one of the first that they made in the early 90s and it has been used and has worn (or not) extremely well over the years.
If a plane body flexes enough to affect the cut, then you need a decent quality plane more than anything else. Any movement in a good quality casting is likely to be un-measurable and irrelevant in woodworking terms – besides, if your blade is properly sharp downward pressure is not necessary to ensure a decent cut.

As far as Jointer-planes are concerned…. No 7s and No 8s – the secret is in the name.They are intended principally for jointing board edges prior to gluing using the rub method….and there is more than one school of thought on whether they need to be absolutely straight……. there’s always the use of jointers dogs where you do need a bow in the middle, so there’s no need for a long plane in these cases………. Alternatively, I don’t see a role for long planes like that in flattening boards; planes like a No 4 or 5 are surely good enough. The extra length just gets in the way.

How long is the plane? The one I have is a trying plane (by the older texts definition, at 22 inches). Said older texts (a pdf version of Turning and mechanical manipulation Vol II from google books) would say that you should apply a jack plane, then a trying plane, then a smoother for flattening a board.
So if this plane is a jack plane, and you already have a metal one, then this is an exercise in restoration and use of older tools, and if you can get the landlord to part with it at minimal cost, so much the better. (And they are lighter and easier to use over long periods.)
Last time I went on HMS Belfast with the kids, the workshop area was the most interesting area for me, as there was a large set of wooden planes there.