I found a way to make my own NVRAM module
The alignment prongs were snipped off the battery holder, then it's glued with CA to the PCB, as is the upside down DS1210.
I had a nasty surprise at the end, the spacing is 0.1" wider than the DIP socket. But with some pliers and gung ho, I was able to bend the header pins into alignment (they are soldered to machine socket pins, those remain perfectly straight). After that trauma, I reflowed the solder on the pins to avoid stressed joins.
With this, I can load software on the HC11 board, then pull it and put it in any prototype.