Hi! You made a good straps!
About glue... I am using Russian glue MOMENT http://www.maxidom.ru/upload/iblock/...bee09474f0.jpg I think this is the best glue which can be purchased here in Ukraine.
What about holes - I am use hole maker like this http://ecx.images-amazon.com/images/...dL._SY355_.jpg and the pattern of the plastic with which to mark up the holes. I ordered a template on which the company manufactures various products from metal and plastic. But it can be done very simply to find some detail where the holes are located exactly in a row.
I hope I could help you
if there are other questions - with great pleasure that I will answer