Bill, I think the post regarding encouraging the bottle neck to form around the front of the mould by using a leaver was one of mine.
I was moulding the canopy for the Saetta which had a very sharp angle on the front screen.
I found that it helped to mount the mould onto a wooden block with a horizontal groove in the front face of the block. The idea was that the bottle plastic could be tacked to the rear of the block as it extended out of the rear of the bottle. heat could then be applied to the bottle working from the rear going forwards shrinking the plastic as you go and taking up the slack. The blade of a large screw driver was placed through the neck of the bottle into the groove and then as heat was applied around the neck of the bottle at the front of the mould the driver can be levered downwards to prevent the neck from riding up on the mould and at the same time forcing the plastic down over the sharp angle on the windshield.
You need a good supply of bottles as I've found that it's very hit and miss and there are so many variables that each attempted can turn out very differently. I hope this helps in some way.