Omg you are amazing, thank you for everything you've contributed to the community over the years.
I know it's hard work, and you'd like to pack it in, but could I recommend one final book? There are still several popular 90s portables without encyclopedias available at the moment: Game Gear, Wonderswan and Neo Geo Pocket. You already have a Portables roundup series - how about completing the trilogy to cover these last three?
I've looked literally everywhere, and these are really the only consoles of note left (besides Intellivision, Atari 5200 and ColecoVision) that don't have encyclopedias of their own.
I've printed every one of your books, and would love to round out those last gaps. If a donation would motivate you at all, consider it done.
But even if you do stop here, you've done an amazing job, and I'm very grateful to you.