Draw file octagon barrel...best choices?|Restoration, Repair and Maintenance|Forum|Winchester Collector

I’m looking for some recommendations and tips on draw filing an octagon 1890 barrel.

What type file do you find best, American pattern single cut smooth files or Swiss pattern double cuts? and if Swiss , which grade cut? 4,5,6 ??

Best brands?

Also any particular length file easier to get nice flat smooth edges?

Any other tips or recommendations welcomed.

Thanks in advance