I was lucky enough to examine and photograph hundreds of tsuba from the Church collection at the Ashmolean Museum in Oxford in January. The photos turned out really well (even under fluorescent lights), however I signed an agreement not to share them with anyone. You can see them in the Church collection catalogue anyway. The museum staff were great and allowed me lots of time to go through them all.
Although I arranged this through a friend who knew the curator, I think most museums are accommodating if you ask in a courteous and professional manner and let them know that you're a serious collector looking to learn.
Well done on deciding to publish your photos/write ups. I for one will be looking to purchase a copy.