it is perfectly legal to drive it TO and FROM a prearranged MoT appointment, if necessary to get a second opinion that may be what you have to do.
If you trust the place where it's at, ask for a written quote, not an estimate, and then duscuss if you can cut it by eg doing the lights and the battery security yourself.
You really need their expertise for welding, a time served mechanics job, but you don't need to pay for the Receptionist's coiffure or even the "complimentary" coffee. We had similar problems with our brakes, sorted here in France, but the overall bill was not cheap as I think they replaced everything from the rubber down, it included slave cylinders (two ?), master cylinder, and some discs, it had only done a few hundred miles that year......
Note to self;
get MrsW to take ours for a drive (my licence is still with the French authorities so no driving for me for the foreseeable future).