Palm sanders for the most part are less effective than hand sanding. Their main advantage is a very even distribution of the scratch pattern for finish sanding. Some random orbital sanders are pretty fast. Often you can improve your removal rate hand sanding by experimenting with different papers. 80 grit is coarse but has less points for rapid removal than finer paper, so experimenting with coarser and slightly finer paper.

Also back some strips with filament tape so they are really tough and bootshine the tubes. Be careful about getting heavy scratches in the metal doing that though. You can also hold the strip down under your thumb and pull it through. Or get some cloth backed rolls of 1".

Some wire wheels are pretty effective. You want a reasonable size one being driven by something like a 4" grinder. A 3m Scotchbrite type wheel can be very agressive.

Not saying chemicals or media blasting wouldn't be better...