Oh my. That looks like it just came from the bottom of the nearest bay. If it were for sale in the States it may be a different story, being parts for them are inexpensive and easy to come by. A new bed is under £40 here. I have a feeling they will be more in your area, and that is the part that seems to be most affected, and is also the part that needs to be done perfectly if you are to have a machine that will work as these should.
If you can get it for half the asking price, it may be worth the trouble. Trouble is what it will be, too. There is a lot of work here if you expect it to perform as it should, which would normally be stellar.
One thing about this, the bed is small enough that you could lap it flat on a large surface plate, if you are good at that kind of thing.
How much does a new one run in U.K. money?