Suggestions welcome- ‘46 runs rough when warmed up

[Mart]

Could there be something causing the carb to run rich? I had a similar stumbling on my 41 pickup and the power valve was not seating properly. Do you need choke to start it? Does it run fine from cold without any choke? This could indicate over rich. The only part of your description that would not point to over rich is that it idles fine hot or cold.