I have finished the building now and just have to bolt in the motor and fit the tank. I will report on the how my version flies later
The weight as it is in the pictures is 20.3oz which seems to be nearly 4oz less than the 24oz reported in the article about it. I haven't done anything to hold the weight down in fact just the opposite The covering is Oracover transparent rather than the slc of the original, the model has had 2 coats of 2pack clear fuel proofer and the red was applied over that and a further coat of the fuelproofer applied over that.
I will update the drawings and templates I used to build this model and make them available. I also had plans to get a couple of part sets laser cut and build a couple more. I also have to make a leading edge cutting jig as the ones I used for this model were rather compromised by my not knowing how to jig them.
Thanks to everybody who has helped me getting data for this project.
There will be a bit of a delay in finishing off the drawings as my wife died last week and I am a bit lost without her.

