Yes it does because it supports the door hinges and the footwells and the brake & clutch master cylinders, and the screen etc etc. any corrosion within 30cm of any of the above items is a fail.
If you run out of time, bodyfiller a good sanding and some paint will hide it. They don't tap the body work unless they suspect rust, the bulkhead being what it is they won't see any rust signs if you fake them all up. CharlesY's lightweight had an MOT when he bought it and it had a bodyfiller bulkhead, i.e. ALL bodyfiller!
Im glad someone has posted this thread as mine is the same, I can not weld so I would have to get someone else to do it for me, is it a long job ? and what would I be looking at price wise ?
it's a fiddle to do it properly - if you just want the job so so am sure you'll be able to find someone who got a mig for xmas to do it for some practise
or pay a proper garage to do it and part with a couple of hundred quid
or buy yourself a mig, a grinder and some small hand tools and diy
expect to pay that for a fully prepped and painted repair - less if you do some prep and dont want it painted - much less if you don't want a proper job doing and free if you find someone who needs some welding practice
i hear MHM is a bit of a welding god these days (now that he understands about gas flow rates)
As I understand it. corrosion within 300mm of a body/chassis connection is a fail.
You don't have that problem, so you should be fine for the MOT.
However. The only roll over protection in a standard Landy is the bulkhead and screen. (The B posts stop at roof level). So weaknesses there are something you really don't want. You're relying on:-
1 Integrity of the bulkhead
2 Integrity of the windscreen surround
3 Location of the screen by the hinges and bolts which position the surround (which rely on their location through the roof and the bulkhead.
I really wish people would research their answers before they post opinons paraded as facts.
A vehicle may be fail it's MOT, If there is any corrosion within a 30cm diametre of a body mount or "safety critical component" in this case that would be the brake servo and brake master cylinder as well as front wing mountings and door hinge mountings. and probably a few other things I've forgotten about. So any corrosion anywhere in the bulkhead is likely to lead to your landy failing it's MOT.