I need softer rubber feet for my ThinkPad P52? Where might I find something?

[LTE]

I recently got a P52 (used of course). Oddly, it wobbles enough on most surfaces to make typing tedious (even though the keyboard is the best I have ever used) --- but my long-time ThinkPad E560 does not wobble on any surface.

From any angle, I can see no distortion or warping of the P52's chassis.

OBSERVATION: The feet on the E560 are subtly soft, but the ones on the P52 are rock hard.

DIAGNOSIS: Three points define a plane, so a 3-point structure is stable anywhere (e.g. a tripod). A STIFF 4-point structure will wobble unless the four contact points happen to define a perfect plane and happen to set upon a perfect plane. Otherwise, two diagonal feet will define solidly stable LINE, and the structure will wobble between alternately between either one of the other feet being in contact. A parked auto is always stable on its 4 wheels because the suspension gives enough for all to contact an untrue surface.

FURTHER OBSERVATIONS: In a discussion on Reddit about this problem with P53 ThinkPads, an experienced technician said that some of this model have the problem and others don't. I suspect different batches of feet for this model have different stiffnesses. And I suspect that the button feet on my E560 have an air pocket inside; not so easily done with the rectangular feet of the P50 through P53 series - so a rubber that is softer seems necessary, but still hard enough to wear well. I putting up to four layers of 0.3 mm gaffers tape over one of the three legs, which helps a bit but isn't a cure (it's still a hard 4-point structure).

NEED, AND A QUESTION: What I need to do is find softer feet for my P52 (or maybe just one softer foot might fix the problem). Do you have any idea where I can find feet sure to be softer, or what softer material that would be durable that I can use to make my own?