Welcome Steve 3 mm it's a challenge. As for the BLUE thing don't worry it will all come out in time. Another thing we have a brilliant number on this forum who scratch build things it's a joy to watch so lets see loads and loads of the pictures of what you are doing.
The BLUE brigade will have to retire to the fallout shelter at this rate
PS the most expensive actual work bench with no models or tools on it is worth £1200( by don't let his misses find out)