Reloaded and installed Samsung 860 1TB SATA SSD

Welcome!

I have since installed a 1TB Samsung 860 SATA SSD m.2 with a 2.5 inch adapter enclosure

Did you install that in the optical drive bay? If so, on the Late 2008 Macbook Pro, the optical drive bus is also SATA 3GB. On earlier Macbook Pros it was half that or worse!

No NMVE in that model. I can confirm that the presence of an NVME category in the left Contents pane of System Profiler is completely generic. I just checked my Mid 2012 non-Retina Macbook Pro which I know has only an SATA 6GB drive bus and the NVME category is there:

In your Late 2008, max possible write/read speeds in the real world with a 3GB SATA SSD on either bus are no more that about 250MB/sec. That is 100% a constraint of the drive bus. Have you run a drive speed test on the Samsung to check for actual speed? If it is much under 250MB/sec, there may be some issues with the install, most likely the adapter.

👉🏻 TIP: They say good judgment comes from experience gained through bad judgment. I offer a tip based on a moment of my bad judgement:

Did you engage TRIMforce when you installed the drive? I discovered only much later that TRIM is beneficial in spite of recommendations from my SSD's maker. After about 3 years of service, the SSD Write speeds started dropping, eventually reaching bad HDD speeds of 60MB/sec. Enabling TRIM plus multiple Safe Boots restored the performance (~500MB.sec in a 2012 Macbook Pro) and it has stayed at peak perforamnce.

It's great that you've already upgraded the storage and memory on your MacBook. However, the hardware section listing NVMe devices you saw might be for compatibility purposes rather than indicating that your specific model supports NVMe drives.

The late 2008 MacBook likely doesn't have native NVMe support in its hardware or firmware. While you can physically insert an NVMe drive, it may not be recognized or work properly. You might need to use an SSD with a SATA interface, like the Samsung 860 SSD you've installed, for optimal compatibility and performance.

Installing an NVMe drive in a system that doesn't support it might not provide any significant performance gains due to the limitations of the system's architecture. If you're seeking substantial performance improvements, you might consider upgrading to a newer MacBook model that supports NVMe natively.