Rover owners: Rear N/S brake binding

Hi, noticed rear N/S brake binding on Rover 45 on Friday, judging by pad wear compared to O/S it's been doing it awhile, took it to local mechanic along with a refurbed caliper, he said he found seized part as in pic (I think, don't know why it not showing my red circle but I believe it is the handbrake connector at bottom middle?) that he thought was the problem and after freeing it said that he thought that the auto tensioner would free off over a little time, initially it felt better but after having done about 200 miles organizing my Mothers funeral over the weekend, I think it is back to square one (burnt my fingers touching the disk after driving one mile last night!) Is it just a matter of fitting new caliper? It should have new pads but I doubt I can get any today and I don't know yet if the mechanic will be available to do it on a Bank Holiday anyway :mad:. I have the funeral tomorrow (two hour drive) so am a bit desperate!