Bulkhead reassembly after repair

So, I’m finally at an important stage in my ground up rebuild of my 79 S3. The bulkhead has been repaired (standard pillars and footwells). Couple of questions to now ask. Firstly, there are slight alignment issues in bolting the drivers side footwell you the upright chassis mount (the one that holds the steering box). With everything loose (including the chassis bracket I think I might be able to force it or at best some slight elongation of the 4 footwell holes will help. I’m guessing it’s important to try and keep the bulkhead roughly at 90 degrees to the chassis and this can be a hide but the aluminium packer pieces ? Secondly, I’ve a non original brake servo setup. When I removed the brake pedal assembly there was a blanking plate under it- as would be fitted to the non passenger side. It has a aperture for the brake light switch cables to go through. I’ve got two new gaskets for the clutch and brake pedal boxes - do I put the steel plate back? The footwells are yrm and so are missing some holes etc. Certainly the second plate would stiffen the box. I also need to fit an accelerator pedal stop as mine was missing - the old footwells had been well bodged . Is there a particular Distance to work too? Sorry lots of questions! Thanks guys!