I just got one of these at a pretty good price and the aftertouch is stiff to say the least. At first I thought it just wasn’t working. I did find that pressing in the center of the keys helps a little bit. I’m wondering if the bushings being probably old and hard means the keys aren’t moving much when pressed upon and if replacing them with newer squishier ones would help with this or if the results would be negligible or nonexistent.