Once again I return with more information.
I've found that the Windows Update catalog retains historic BIOS information along with other driver details for ours and many other machines. Somewhat expected but lesser known information I suppose.
Anyway I found out that the entries in the WU Cat tie to a supported hardware ID which is how they are delivered to your machines.
Using this I went into Device Manager then expanded "Firmware" then opened object "System Firmware"
I then went to the "Details" tab and selected "Matching device ID" in the drop down.With the value in view, I right clicked the entry and selected copy.
Afterwards I went too https://www.catalog.update.microsoft.com/Home.aspx and pasted in the copied hardware ID into the search bar. I could then see all the BIOS updates suitable for my machine.
