Thanks, I am still looking into the options available to me on this movement. Its an odd issue thats for sure. Everything fitted as it should, and everything works as it should, and then suddenly the spring will dislodge, and rest under the date wheel.
If I apply light pressure to the date wheel, then all is fine and dandy, and whilst this may point to a temp solution of using expanding bonding on the overlay, creating that downward pressure from the fitted dial, things would work, but I would not be happy with this solution, and consider it a bodge, so looking to getting this done right. ETA parts are my next port of call though thats for sure.