As I suspected, I could not let go of this. I did some more research on the subject of my
previous post about this. Then I made a slightly different change to the keyboard section of /etc/X11/xorg.conf:

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option       "XkbModel"  "pc101"
	Option       "XkbLayout"  "us,us(intl)"
	Option       "XkbOptions"  "grp:lwin_toggle"
# In the last line above, replace "lwin_switch" by "lwin_toggle"
EndSection

This way the left windows key is simply a toggle between the two keyboards; I do not have to hold it down while typing the accents. I got this from the Gentoo Wiki:

1. grp:switch — toggle using right alt key, but only until unpressed
2. grp:lswitch — Left Alt key switches group while pressed
3. grp:lwin_switch — Left Win-key switches group while pressed
4. grp:rwin_switch — Right Win-key switches group while pressed
5. grp:win_switch — Both Win-keys switch group while pressed
6. grp:toggle — Right Alt key changes group
7. grp:lalt_toggle — Left Alt key changes group
8. grp:caps_toggle — Caps Lock key changes group
9. grp:shift_caps_toggle — Shift+CapsLock changes group
10. grp:shift_toggle — Both Shift keys together change group
11. grp:alts_toggle — Both Alt keys together change group
12. grp:ctrls_toggle — Both Ctrl keys together change group
13. grp:ctrl_shift_toggle — Control+Shift changes group
14. grp:ctrl_alt_toggle — Alt+Control changes group
15. grp:alt_shift_toggle — Alt+Shift changes group
16. grp:menu_toggle — toggle using “context menu” key on Windows keyboards
17. grp:lwin_toggle — toggle using left win key on Windows keyboards
18. grp:rwin_toggle — toggle using right win key on Windows keyboards
19. grp:lshift_toggle — Left Shift key changes group
20. grp:rshift_toggle — Right Shift key changes group
21. grp:lctrl_toggle — Left Ctrl key changes group
22. grp:rctrl_toggle — Right Ctrl key changes group

Possible signs using grp_led:

1. grp_led — use keyboard leds to indicate group change
2. grp_led:num — Num_Lock led indicates group change
3. grp_led:caps — Caps_Lock led indicates group change
4. grp_led:scroll — Scroll_Lock led indicates group change

if you have problems with setting up your keyboard, /etc/X11/xkb/README.config will be most helpful for you, so make sure to read that file

I could change the line

	Option       "XkbLayout"  "us,us(intl)"

to

	Option       "XkbLayout"  "us,us(intl),ru"

which would include a Russian (Cyrillic) keyboard in the toggle rotation. This is about 40 years too late. When I was taking Russian back in college I often wished I had a Russian typewriter. I am sure that my professors, who had to contend with my handwriting, also wished that I had had one.