It boots!

I have attached the Individual Computers RTC Module to the Individual Computers ACA1233-40 accelerator card and installed the latter together with the Individual Computers AGA MK2cr flickerfixer as well as the Kickstart 3.1 (V40.68) ROMs.

I connected the Amiga 1200 to the display via DVI and, without connecting a keyboard, mouse, or floppy driver, turned on the power. And waited for everything to crash and burn. But against all odds (at least if you believe some forums on the Internet) my Amiga 1200 came back to life.