I don’t see anything in the UK MOT Manual that alludes to rusty springs being an advisory or a failure?
Axle, wheel bearing, wheel and tyres, tyre pressure monitoring system (TPMS), and suspension (including springs, shock absorbers, and suspension arms and joints) rules and inspection for car and passenger vehicle MOT tests.
www.gov.uk
I believe that some MOT centres that are attached to working garages or may have some arrangements with close by garages try it on and if one had gone else where they would not have pointed the same thing the last place may have brought attention too.
Years ago I was over in England and was attending I think it was a county council MOT centre. I can not actually remember where it was but probably not a million miles from the Bristol area. I took a vehicle or two a couple of times. I expected a hard time one vehicle was oldish so would not have been surprised if they found something niggly to point at. I waited a little while had seen some vehicles fail before it was my turn. They where extremely attentive and appeared very thorough, pulled at this and that. The vehicle passed he said it was OK but advised I look at where the McPherson struts and he pointed out some surface rust on the wing. He said some places might fail it but it was not structural and demonstrated by rubbing it and most of it just disappeared in seconds. He just said it is superficial and not structural but clean it up no need to paint over it but keep an eye. He had no axe to grind and and did not benefit one way or another and he had a little chat about MOT stations. I think that I returned the next year, can not quite remember. A Year or two later and I took same vehicle to somewhere local hear it was a scruffy down trod place. Did not want me around when they did it and it failed. They found a couple of rust pimples I explained but they would have non of it I was referred to the garage down the road. Their it stayed for a month or more and eventually the vehicle was ready to take home with an MOT. I examined the work and it was appalling the mettle work had not been cutaway professionally and the repair was shocking with very poor welding! It was in a worse state and I had no doubt would fail future MOT requiring some more expensive restorative works a month or two later I scrapped it feeling it was unroadworthy. The MOT was issued by exactly the same place as I had it failed at.
Given advice by a neighbour to take one of my vehicles to such and such a guy living in a council house with some back of the place yard with quite a few old vehicle. I knew this particular vehicle had one or two things needing attention but wanted a ball park starting place I think it was an other 4x4 I think it was a Jeep or Merc along time ago. I had to continually go around and ask has he looked at it. It was not an MOT station by the way but he worked at an MOT station and Garage and also did some private works at home I had never met him before. This went on for a few more months and I was becoming very irritated and wanted to take the vehicle else where because it MOT was now due. All I wanted was him to find fault or not and attend to it or send me else where to have works done or have taken it to work with him for its MOT A little while later the vehicle had been done and had its MOT So I trundled round to pick it up. It was in exactly the same place that I had parked it ages ago and it did not appear to have been moved. Paid him his money and drove off with afresh MOT was happy at first and relieved. I recall now one of the things that I wanted sorting, it was a leaking fuel tank or filler neck that leaked fuel on the floor if it was near full guess what it still leaked. Went back complained his reply was a curt, "it passed didn’t it" . FFS never went that way again always chose places that seemed professional

and took no notice of neighbours ever again. I say neighbours but farms here are some distance away from each other and yet these people are refereed to as neighbours. I had a period of buying second or third vehicles that where older but serviceable as a runaround that could be kept going for a while, passed on or exchanged or scrapped if too expensive to continue with.
As a side note the garage where this guy worked evidently as reported in a local news paper suffered a brake-in where its MOT BOOK was "stolen"!
It is preferable to go to good honest MOT stations that do not profit either way where that is just a job and they do not do any required work work. I am unsure if these days MOT Stations are run by local or otherwise government but think they are in the past but would be the best solution and totally independent.
I imagine that this may be or has been a common thing in country areas. Certainly one passes roadside places with very scruffy vehicles waiting for a 1 year only buyer and that their may be loads of unroadworthy vehicle driving around, all seemingly legal with MOT, when in fact they may not be road worthy at all and even possibly dangerous. I had following the local thing and most of the locals wondered why I was so displease as it had now an MOT.
