It's really not a hard job in a 7 but if you are looking for someone to quote the I have found a card from M&M classic car components that can do this for you.
www.m-mclassiccartrim.com
Email mandm@talktalk.net
Phone 01775762004

I know i sounded a bit vague but I really dont know much about cars. I just know that its great fun to drive. The cable looks a bit thicker than the other ones. It looks like it screws in somewhere as it has a threaded end to it... Again I know I sound stupid but unfortunately I am with cars... And with the interior I just want a decent job doing and would rather not stuff it up myself like the last bloke

Just have a go mate. Before i built my car all i had done was lower a few hatch backs and put induction kits in them. Now i have loads of tools and new skills. Now you own the car if you're going to pay someone to fix it every time it breaks you're going to need deep pockets

Does the cable you speak of come from the back of the speedo by any chance? If so I'm sure someone can tell you where it should go. It would certainly explain you lack of speedo.

Yer it comes out the back of the speedo. Its not plugged into anything tho... Any ideas?

Then its the speedo cable and it probably does go to the gaer box. What engine has it got?

it turns out that its a sensor run on the back propshaft, the magnets may have fallen off but not sure. As I said I dont know much about them. Getting it on a ramp tomorrow to check then hopefully I should be able to know how fast i'm going

you are getting there , you just need to get inventive and you can solve most issues yourself . if it needs a new cable then so long as you have both ends and the correct length Europa can make one up to fit

I fixed it now. Turns out the magnets had come off the prop shaft. Glued new ones one now and working fine