I have an M&P Shield with the GREEN Crimson Trace laser, great product, but...
I can find any leather holster maker to make a good IWB holster.

Well, I did find one leather holster maker but the quality was so poor I returned the holster.

Ideas?

Well you asked for ideas...so in leiu of leather, how about a kydex / leather hybrid.
There are several out there that will accommodate your laser.
I found the Theis single clip to meet my needs

Product Details

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M&P 9mm 5" Pro
M&P 9mm Shield

Yeah I may have to "settle" for kydex or a hybrid, was really hoping to find an all leather holster. To be honest I did not think it would be that difficult.

The Green laser is a different size from Crimson Trace's Red laser. Everyone has the ability to make a Red laser holster but the Green is what I have.

To be honest if I had known it was going to be such an issue I would have just kept the Red laser and not gotten the Green.