I went over to Polly Models this morning to sort out the reverser.
It turned out that the reach rod and pole were fouling on the spacers in the pole frame limiting the travel of each. Matt at Polly took charge and removed some material from the reach rod and reduced the bend. He then tweaked the racks for the latch and the spacers.
Having got that sorted, Matt helped me setup the rough valve timings out and I bolted up the steam chests and attached the steam pipes.
Time for the big test, would she run on air?
She was a bit lumpy at first but we had her running for about 30 minutes and she became far more compliant. After that we tweaked the valve timings by half turns on the valve rods. 
The final result was a very smooth run for another 30mins running on as little as 20psi.
At the end of it all I was delighted; really chuffed to have got this far and to have built something that works. It is now lovely and smooth and easy to turn the wheels by hand albeit now a lot more oily!
Just got to sort out the drain cocks (I have put a couple on the wrong way) and to attach the drain cock activation lever.
Building Molly Ann 
Hi there Dikky,
I hope the train is still going strong like my opinion about marmots. Lovely to see you still at your engine instead of chopping off fingers.
Lots of love from your mate,
Toni boy
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