Westminster Chime Spring

[Solster]

A friend asked me to 'have a look' at the Westminster mantle clock he'd got himself cheap. Even with my (very) limited knowledge I can see that the movement is in a poor state - there's old residue and new oil everywhere and there are some non-original looking screws and springs in it! But to cap things off as I was letting down the chime spring it broke! I'm not even going to attempt to open the casing, but was wondering if it would be worth getting a new one that comes as a sealed unit? It comes off the plate(?) sideways and is easy enough for even me to do! Can anyone give me advice on what it might cost and the best place to get one? It's a Smiths K6A movement with the body date stamped with 1954 (not sure if that's manufacture or service).

Apologies for no photo, but I've put it back in the case for now.

[oldhippy]

I really need to see the movement. 

[Solster]

Okay, thanks OH. I'll get a photo soon.