Davy, sorry about the knee's! I am the same way when down on them they hurt a lot also. But to be honest sometimes the hardest part is just getting back up! LOL
The Engine is looking really nice! Its going to be a sight to see running around your garden! The track work also looks great! I am glad your almost there and hope you did get a chance to run a train around it yesterday! When you do get it running if you can a nice short video would be great to see!
I hope you have a great day and the sun gods are with you today!