RQ: Pistol Daimyo no Bouken

[The Eidolon]

I'm trying to get as far as I can into this game, and I keep
getting stuck. It appears that after you finish three of
the five "tracks," you go to a bonus (penalty?) stage where
you face a series of bosses who reside in pots and then
some kind of a giant tank-like wall monster. Unlike all the
other stages I've seen, once you run out of lives, it
disallows continues and you have to start over completely.

Has anyone ever gotten past this point, or finished the game?
Is there a way to avoid getting sent back to start? It takes
me nearly an hour to struggle through to that point, so it's
hard to get enough practice to improve on that hidden stage.

Any useful links or commentary about the game in general
would also be appreciated. I've been working on this one for
years and I'd love to see the ending someday...

Thanks, --The Eidolon