It's not as bad a job as I expected. Fitted my hood last month. Use lots of masking tape and take your time. I didn't build my car, and most xperience I have is replacing hubs, brakes, fuel tanks and radiators! I did similar to Paul, except I didn't fit doors first just lots of tape!
If you don use poppers on front window screen, use caravan awning. I need to change mine then will be 99% water tight!
My dad found a classic car upholsterer to fit a tonneau to his tr. was a long wait though, and expensive.
Ed