Matthew, I had a 146 in the mid '50's that had the same draw stops as
the 146A and 146B (and also 145 and 145B). My experience is limited to
a sample of 1. Also it has been my experience that the Wurlitzer
factory made frequent changes during a model run. I am not certain
that they are all the same.

I think it would be fairly tough to tune a 146 without draw stops - but
perhaps one could stuff rags into the pipes to keep them from sounding.

This is my very limited experience.

Also, consider pulling out some of the pipes in the ranks that don't
play and look to see if you can identify what's holding the wind back.

I am interested to learn what you find out.

Bill Finch