I am assuming that both frames fit, and neither frame has rust, dents, nor significant paint damage.

If this is not the case, always buy the frame in better condition, regardless of label prestige. A dented Nagasawa is not worth the same as a pristine Bridgestone. Similarly, with regard to fit, the Panasonic that fits you is infinitely better for you than the Samson that is two sizes too small.

Of course, if they are equal in the above respects, the Eimei vs. Makino debate comes down to pure aesthetics. Makino has a more famous name, but is a bigger manufacturer. Eimei is a much smaller shop.

Do you want the frame that everyone knows, but more people have? Or the frame that gives you exclusivity at the price of a little anonimity?

How did you pick those two brands to be your favorites? They seem like pretty disparate choices.