Wow okay lots to consider now and thank you everyone for your input, I appreciate that the knowledge required to fully appreciate the skill involved and history of Japanese sword making eludes me as yet and possibly always will.
Yes I am influenced by the Koshirae when I look it completes my desire in a sword but is not a deal breaker.
Being Mihara school era is not a requirement for me I am open to different eras but antiques and history and the associated romance is where my interest lies.
Finally if only I was fluent in Japanese and had very deep pockets it would make all of this a lot easier, sadly my tired middle aged mind is no longer sharp enough for the challenge.
I will continue my search for a Tanto and reflect on the wealth of experience gifted to me in these replies obviously I need to spend a lot more time on this bleeping computer searching and learning, RIP my eyesight.
Thank you everyone for your feedback it has been truly appreciated and hopefully any input in the future from me will come with a touch of wisdom fingers crossed.
All the best to you all.
Regards
Steve