this is absolutely beautiful mate. thinking about getting a westfield myself and having made a removable roof but made of carbonfibre. very similar shape to yours though.
Nice work. I have often thought about this and my solution to ingress/egress, would be to hinge the entire top from the lower back, with lifting struts and clamp it to the windshield frame when down, with say, MGB clamps, or similar.
Looks about as good as it ever could, but I still bet it would be virtually impossible for anyone over about 5'.11" to get into it. I've got a Fraser and I find it impossible to get into the thing once the fabric roof is on. Maybe, if you get a detachable steering wheel it could be done, but otherwise, not a chance.
I take it you have never taken your 7 on holidays. If you need to cover a long distance in the blistering sun then a roof is extremely comfortable. Having an aluminium roof instead of a canvas one reduces the noise of flapping fabric.
I have owned two original Lotus 7s . They come with (soft and detachable) roofs my friend. Being macho is one thing. Looking like a drowned rat is another.