SOLUTION for ELO touchscreen on tinycore linux
Start off with a mouse plugged in as well, you'll need it at least to get going...
remove Xvesa and add Xorg,
OR start with frugal/text and go straight to Xorg without Xvesa
dmesg | less
/ (find) ELO <Enter>, or > (go to end) and arrow up to check that the screen is being recognised by evdev
add the extension xinput-calibrator-tcz, this should add the calibration program onto wbar
Run the calibration tool, screen should dynamically recalibrate so you can test it live before making the permanent conf file
Take note of the terminal output from xinput-calibrator
Create a new file as instructed 99-calibration.conf, at /usr/local/share/X11/xorg.conf.d/ (same place as 10-evdev.conf)
I used vi for this (in a separate terminal), press 'i' key to insert in the new file, scrape mouse over the output snippet from xinput-calibrator, leave it highlighted, then click back inside the vi window and press shift+insert to paste. Careful of the word-wrap in output from xinput-calibrator, I had to touch up the Match line by removing a bunch of extra spaces
ls -l to check it's there, and cat the new 99 file to verify the contents.
Add a new backup rule (control panel), and include this new 99 file in the list of things to be backed up
Reboot and test
Hope it works for you too.