You dont' have to cut the footwell.
I have built 3 RHD chassis and have had sufficient clearance for a side exit distributor cap for all of the late chassis examples which have the plastic footwell side panel. It is a tight fit, for sure. but the cap does fit, without any contact, and wont be knocked off the distributor on a hard shift. Remember, the cap has to be fitted to the distributor AFTER the engine is in the car. You should be able to remove the cap, rotor and remove the distributor from the engine with the engine installed. It's a tight fit, but it does come out with the clamp. I fit the distributor to the engine after I put the engine in the car.
Check that the distributor clamp is fully engaged on the distributor body (as far up as it can go), and that the distributor is fully home, as well as the distributor drive gear properly installed into the engine.
I selected a non vacuum distributor, as I run a big Weber, and there is not enough vacuum to even make the vacuum advance work. This gives a bit more clearance around the distributor. I also eliminated the main oil line between the block and the oil filter mount by connecting my oil cooler to those lines. This gave a much cleaner installation, and a lot more room to adjust the timing or to R+R the distributor.
USE A SIDE EXIT CAP, ALL LEADS ON ONE SIDE. This will help with clearance. Your current cap has leads where you need space.
Also, make sure that the timing mark is at TDC on cyinder #1, and that the distributor rotor is aligned with cylinder #1 in the cap (this could be any of the contacts. You just have to know which one). All this helps to get the cap in place, and make it relatively easy to remove. It is important to check the position of the distributor drive gear with the engine at TDC (both valves closed). The correct position is shown in the engine manual. Note that the gear notch is wider on one side, so that the distributor goes in only one way. This is important.
Of course, given the difficulty of removing the distributor cap, it is imperative that a Pertronix Ignitor or other magnetic trigger is installed to replace the points. This eliminates distributor maintenance and re adjustment of the timing once it is properly set.
Make sure that the engine is where it is supposed to be. Rock it into position (you might be surprised as to how much extra clearance you can find). Check to make sure that you don't have a washer in the wrong place (a washer under the engine mount can cause all sorts of distributor cap fit problems).
The build is not difficult. I found that the single hardest thing to fit into the RHD chassis was the brake pedal (my builder's suggestion is to start with the brake pedal, because after that, everything else is easy, even the tricky fit of the distributor cap onto the distributor, once the engine is in place. I put together the rolling chassis in about a week, and the engine installation went smoothly, including the transmission mount for the T9.
I did make sure that I had the rear axle built (brackets installed and welded) prior to the chassis arriving, so that there would be no delays in getting the roller on the ground.
Take a look at my westyxiownersbuildersdrivers site (we have 30 builders there)
https://groups.yahoo.com/neo/groups/Wes ... ivers/info at Yahoo and check out the RHD build album. Join if you have not already. It might help you. There are lots of pictures of every phase of the build, and every assembly. If you need additional pictures, I have them.
This really is not a chore to build. Not exactly like putting together a Noble M400 (I did two of those, including the US distributor's magazine test car in my home garage (It blew the doors off of every production car it ran against, and proved more reliable in every comparison test). Our Nobles came to the US without engines and gearboxes. Owners (or a shop) had to install the twin turbo V6 on our own), but the W11 is not really that hard to do.
I finished my last RHD car in less than two months (engine, transmission installed into a rolling chassis, wired). There were delays waiting for things like the custom radiator and the header. But there were no delays in the garage as far as assembly, or light fabrication of the front air duct. or the front bonnet bracket braces. it went together smoothly.
I even installed twin brake master cylinders (the firewall is already drilled for them, and the balance bar brake pedal is available from Westfield), making up my own brake line setup using a couple of short flex lines, and the parts that came in the kit. It really didn't add any additional time to the build other than the trip to the shop to have the lines made up.
I understand the frustration. I was lucky that I had a W11 early chassis for a few years before rebuilding my first freshly built, new production RHD chassis, followed by a second, then a build from the crate. I had a lot of experience, and found the build manual of limited use at that point. Most of the time spent is usually looking at the parts, and the chassis, then formulating a plan before picking up a wrench. I found that I spent a lot of time figuring out the parts inventory prior to putting on the front suspension. The car, for the most part, went together easily. No surprises (other than the RHD floor mounted brake pedal. a real Chinese puzzle...).
I have lots of pictures, and a whole lot of experience on this chassis, both new and early (as well as extensive A series engine building). Before you pick up a saw,, torch or hammer, post something. The solution is usually pretty simple.