Hey
You really need to upload the picture, if it is too big i dump an image into PowerPoint and then take a screenshot and crop it in MS Paint and then load that up, there are probably easier ways but hey, it works
as for the poster you haven't described it well enough as there are many UK Quad styles. However, if you have the main poster I am going to assume it is a 1977 C design by Tom Chantrell, i am guessing it is not the Hildebrandt brothers version which is the original UK Quad and something of a rare find.
The Tom Chantrell design came out after the Hildebrandt brothers version and came in two flavours, one just before the Oscar wins and one after, the only difference being the printers added the Oscar wins to the poster. Without images there is no way to make a valuation but pin holes and creases are not your friend here (Sorry), that said in 1977 it was common for the printers to fold the posters and ship flat pack to the cinemas rather than roll them, but if they are minimal and in the case of the pin holes in the corners then a professional mounting and frame will hide a multitude of sins and shouldn't detract too much from the value, but it will detract a bit.
As for common/rare, this version isn't that rare but equally isn't super common either, i.e. if you know where to look then it isn't too hard to find, most dealers carry copies and there is always someone on evilbay trying to flog it. The version with the Oscar details on is more common and can go for anything between £200-£350ish at a guess. The version without the Oscar details could get up to £400/£450, maybe a little more but it is all down to condition and market desire. It is a cracking poster, easily one of the best made for SW. Potentially a nice and quiet valuable poster but without pictures you won't get any interest.
Tar
matt