T420 Palmrest: metal parts?

[7rowsforlife]

I am trying to find a replacement for my faithful T420's palmrest. I have put this machine through the wringer over the last 9.5 years, and while the current palmrest is still holding together well (this thing is a tank!) it has numerous cracks, the rest of the chassis has been or will imminently be overhauled, and I know it's just a matter of time before this thing gives out on me.

One question I have as I'm looking at these is about the metal parts typically sold as part of the palmrest - not the touchpad/fingerprint reader components, but the thin metal sheets present in this listing that are not present in this listing. What is the function of these parts? Aside from the one that supports the keyboard over the fan, the rest simply seem to cover plastic in specific areas, and it's not clear to me why they are there. Also, does anyone have experience transferring these parts from one palmrest to the another? I'm quite sure mine are in good shape, but it looks like I would have to melt the plastic nubs to attach them to a new palmrest, and I'm not sure if I have access to the right tools to do that.

I'm struggling to find palmrests in the condition I'm looking for from a seller I trust. Right now, the plastic-only option looks like my best bet, aside from this question of swapping the parts.

[RealBlackStuff]

The expensive one looks like the real deal, while the cheapie looks like a fake or 3D version.
The metal parts are obvious reinforcements.

[7rowsforlife]

What makes you think the first one is fake (other than price)? On the second one, I always thought "New For" was a dead giveaway that parts were not genuine, but compatible replacements.

I'll give you reinforcements around the speaker mesh, but why run a strip up to the screw hole? And how much reinforcement do you think you're getting with that tiny strip around the trackpad? I was assuming these would have more to do with electrical and/or thermal grounding - they do not look very structural to me. I haven't played with them much though, maybe they're thicker & stiffer than they look.

[RealBlackStuff]

No idea why they put on those metal parts, if they were NOT reinforcements.
New one here: https://www.ebay.ie/itm/274657366309

[axur-delmeria]

I think that the metal parts could be for EMI shielding and/or grounding.

[7rowsforlife]

New one here: https://www.ebay.ie/itm/274657366309

Their picture doesn't even have the "ThinkPad" logo in the corner. Did Lenovo really make these parts without that logo?

I think that the metal parts could be for EMI shielding and/or grounding.

If this is the case, I would feel pretty good about transferring them over. I guess having thought about it more - even if they are structural, cutting the nubs off of the plastic and then placing a dab of epoxy or Q-bond or something in place of each nub would probably hold them on pretty darn securely. Hell, I have access to a tiny waterjet machine that would probably crank a second copy of these out with no issues, I'd just need to source a small sheet of aluminum and then bend them carefully.