I waited this one out to see what might surface. To the best of my knowledge, both NCT & Replacement are correct to some extent. I'm still not positive that Miroku does not translate as 'my luck'. It may or may not & I spent many an hour speaking w/Japanese who were post occupation gun owners trying to get a better grasp on the shotgun history there. At best, it remains sketchy.
The gun being described quite likely has chopper lump bbls. and is well fit [& possibly even finished on the inside, some were]. You may not be having to pay much for it due to the confusion w/the name, but I'll assure you it is well above a utility grade gun. Buy it if the price is anywhere close to reasonable and grin all the way home. If the stock is too short, you can add length with a pad or spacer or both and if the dimensions are 'off' it can be hot oil bent, within reason, to better suit your needs.
Appropriate sized shot for the intended quarry in a 20ga. NEVER requires more than 7/8oz. shot, IMHO. Don't get caught up hammering the gun to death w/heavy loads & you'll be quite happy w/the results.
kind regards, tw
Look forward to your pictures as well.
