Hi Simon, I think for a first attempt you did a good job. The untrained eye is unlikely to notice anything too far amiss.
Is the blade completely secure and aligned in the tsuka and can it be removed and replaced with ease? If the answer is yes, then well done on that.
The next time you do one, you will know what you're in for, and the result will be improved further. I have tried my hand at woodworking parts for swords and it is a true test of accuracy/tolerance. I once made a tsuka for shirasaya and the result worked but it took me forever and looked not as good as yours. Anyway, you've done well and there's a serious shortage of people able to mount swords these days. Keep practising and one day people might be paying you to do it...