Ok, using the features of the marvellous PrusaSlicer I only needed one of each STL.
By changing the size Parameters, and using the cut facility, along with a pot of superglue. I was able to achieve various sizes as required including sizes beyond the printer bed size by joining together.
There are also joining clips on the the top and wide joining pieces to aid gluing together on the insides. Again altered as required. Although changing the width of the top clip not recommended
Height is set at 6cm, my draw height.
I used a draft setting nozzle 215c bed 60c. Due to issues at the time of printing i had to use Sunlu and Enon filaments.
Hopefully next time my son places an order I can piggy back his postage costs and get some more Prusament. ½ a Blue left.
The author marked this model as their own original creation.