While a neat curiosity now, and I wouldn't mind having them for the collection. I don't recall any gold topped chips/heat spreaders from Intel except the Pentium Pro line. Also, the very early Pentium I's that were likely to have the floating point error had the gold heat spreader, (P60 / P66) but didn't look like these. As OP mentions they're not original, which is consistent with my memory. All the socket 7 I recall was ceramic and the Pentium 1 era being the start of the fan requirements on them. I also specifically don't recall any of the codenames being a common known thing. (Tillamook) Especially not on chips or shown in the BIOS. Sure we use these terms now quite frequently, but I remember at the time these were new, it was all following the Intel marketing, so it was Either Pentium 1 or 2 with the MHZ rating and sometimes the addition of MMX (did it even do anything except sound neat?) and that was how we talked about Intel chips. They had a premium cost over their competition, but it was pretty simple at that time to compare and keep things straight Intel-wise. They were the benchmark, king of the hill.
That BIOS screenshot is interesting as it (to me) indicates that there was someone or something doing some re-programming on these. I for sure remember it was always (Proudly) stating Pentium in the BIOS and as much as they could in general. They were pushing Pentium branding hard after the years of all the clones able to utilize the 386/486 branding. Pentium was the differentiator, and more specifically a Trademark they could protect.
The other comments about the possible speeds is likely. Although, I might be a bit hesitant to accept that the chips were overly restricted. Remember, on-die cache still wasn't a mainstream thing until the P-pro and PII era. That would always be a limiting factor of speed for the chips. Also, I think Intel really stressed reliability at this time. They're fresh off the Pentium FPU error recall, and it's the era that the ubiquitous 440BX chipset came out. I think you could overclock these chips at the cost of stability. We also have way better coolers now, as back then there were just case fans near the CPU that would have a fanless heat sink attached to them. For their time, I think Intel had them clocked where they needed to be and the lack of onboard cache was always going to be a limiting factor.
Thanks for listening to my rose-colored glasses rant of bygone eras.