I investigated the 7500S and confirmed it was based on newer technology. Careful scrutiny of the FCC database showed that it was indeed different from the 7500. Its FCC ID is QKL7M2 and it has a new PCB, horn and a Motorola DSP. I suspect it is more of a twin of the Solo S2 than anything else. The horn is much lighter than 8500 and BEL RDs, which is the result of its smaller size and the use of a PCB metal layer forming its base.
This may make this a good deal as they sell for much the same price as the original 7500s. It may also explain the degraded X-Band performance as well. Its laser range to the rear is better than an BEL 960. Original 7500 models had the older "spring-clip" horn assembly and another DSP. The 5000 Passport had a TI TMS3200 series DSP, which I believe is second-sourced by a number of FABs, and likely is found in the original 7500.