Mothers Mag & Aluminum Polish, 10 oz. – Brilliant Shine, Easy to Use, for All Uncoated & Unplated Metals Including Aluminum Wheels, Stainless Steel Trim and Exhaust Tips, Brass & More (05101)

From my life observations, everything can be opened up (once sometimes). Unlikely there would be a gasket since there wouldn’t be grease packed inside. If there was it would seep out the ram at the bottom. Disassemble it responsibly and take photos if you’re concerned about rebuilding it. Use food safe grease to relive everything after a serious scouring. There are many aluminum cleaners/polishers on the market. Here’s one I have used. DO NOT USE THIS INSIDE THE PRESS!! https://a.co/d/00tul4xf

Have you tried Mothers Aluminum and Mag Wheel polish? If I'm patient and take my time, I am amazed at how well it brings out a shine. It's also my go to for cleaning up paint on neglected frames.