Just to clarify 020700 is the file name of the executable. In my case the filename of my executable was R610-0~1. That threw me a curve for a while. In any case the /FORCETYPE option to the BIOS installer got me past my issue, so thanks for the hint!
My life is now enriched. Thanks for that /FORCETYPE...wow. I downloaded the EXE un-packaged file of the 2.70 BIOS for 1950 (selected Linux from the OS drop-down-list on Dell support page), use Rufus to create DOS flash drive, copied EXE to flash drive, and then booted to it. Executed the.EXE /FORCETYPE and it proceeded through.