Self Reply: I did some further experimentation and have figured out one workaround. With a bit of post editing, this workaround seems to have gotten the job done for now.

Selecting my personal (“Home”) calendar, I exported that file. Next, I imported that *.ics file into the new (“Birthday-Anniversary”) calendar. Then, I turned off the other calendars and using a combination of search criteria and category-sorts, highlighted those that I wished to edit out and deleted them. That left me a calendar with only the birthday and anniversary events remaining. Finally, I turned the original calendar back on (by itself) and deleted the originals from whence this new calendar was created.

While this was messy, cumbersome, and not very smooth, it ultimately got the job done. I would still be very interested if someone has a better method which might “move” selected events and eliminate the risk in my workaround of double-deleting an event from both calendars. Thank you all.

I'd do this:

• open event search from main menu while on calendar tab
• filter it so that you can select events you need (hold Shift or Ctrl to select more than one)
• cut these (either from edit menu or Ctrl+X)
• select the calendar you want to put them into from calendars list
• paste (again, either from menu or Ctrl+V)

Same select, cut and paste solution works on smaller set of events in calendar view as long as you select destination calendar from the list.

Perfect. Works great!

I was making it too complicated. You offer a simple solution, (which perhaps should have been more obvious to me). Thanks much.

OK I found another easy solution....

• highlight all the events you want to change, by ctrl/clicking on them : they will all change to a beige colour.

• click on "edit"(a pencil icon) in the top task bar

• chose which calender to move them into, on the 'calender' list

all done! ;)