Great comment and observation. Yes, the battery situation has been quite the topic of discussion, where do you try to keep things original looking and where does it make sense to go with a more modern solution?Beautiful car and lovely engine bay, however the modern battery caught my eye. Have you considered using one of the imitation battery toppers. With so much attention to detail I think one would really help with the authenticity.
Obviously, it is very difficult to find a battery in the original GS or Yuasa battery style. Autolite sells a faux battery top that has traditional looking battery caps on it, but it is over styled and I would not think that a Japanese car like this would run an American car battery. I have seen a few roadster owners use them before, and they look cool, but not the style we are going for on this car.
We are not done with this subject yet, I do have some backdating to do on the battery that hopefully will be a good compromise. Watch this space.
Michael