Hey Six, sounds like you got a great deal on a set of forks. About attaching them to your tractor, there are several options depending on how your bucket is mounted and what kind of tools you have access to, welders, torches and a source of scrap steel will sure come in handy when you do this.
I have a Westendorf loader and quick attach bucket on my tractor. Westendorf sells the quick attach mounts seperately for the purpose of building your own custom attachments.
You could go to the dealer and take a picture of the factory setup, take a few measurements and make your own copy or modified version of the original.
I would also look in the Attachments, Customization, Build it yourself and Projects forums here and do a search or ask there if anyone has done this for your particular model already. Even if they haven't built forks for the Massey, I'm sure you can get some good ideas and advice from someone there.
Best of luck and don't forget to let us know how the forks turn out. /forums/images/graemlins/cool.gif