Generally it works ok. However I had one set where adding the watch battery make the set scream with hum. I simply changed the biasing scheme and that took care of it.
HTH,
Bill
On the other hand, it is not all that hard to carefully drill down through the face of the old cell until you just hit the paper. Using the chuck from an old electric drill motor like a pin vise is an easy way to avoid cramps in the hand if a pin vise is too small to use comfortably.
:Hello, I am wondering what change if any would be in replacing my 1 volt bias cell with a watch battery.
You may find this web page of some interest too.
http://www.philcorepairbench.com/biascell.htm