Thanks for the encouragement guys. There are bubbles but I must admit I was very pleased with my first cast.
As the saying goes 'onwards and upwards'
The Brittle Bone Society pen is for my nephew,for his Christmas. If it is ok I will make some up for the charity to sell.
The other pen is for the vet's surgery that gave me the syringes to to get me an accurate measure on the materials I used.
EDIT Thanks Brian that seems to be a super idea, I was using the bandsaw yesterday and it did vibrate.
The only worry I have is that the mix goes quite stiff fairly quickly. The first pour in the bottom is ok as I can get rid of the bubbles, but the second pour gave me the bubbles under the tubes, this is where the problem seems to be.
Any help is welcome