When modding DMGS  (haven't modded much else yet), I find it less than suitable hardworking connections between the PCB boards (eXtra 5v regulator powering a backlight and running off unregulated 5v at the power board, for example) or between the shell and the boards (variable clock, rgb switches, pot for backlight brightness control, for example).  I'd like to introduce connectors on connections between any separate pc boards/shell halves to make disassembly easier.

Can anyone point me in the direction of small connectors suitable for this?

Digikey is a great place to find specific components like this. Just search for connectors and sort by your pitch and sizing requirements.

I like using using small molex or flat flex ribbon connectors, particularly if they are small SMT parts, since they are generally super low profile.

Examples include:

https://www.digikey.ca/product-detail/e … ND/1003008
https://www.digikey.ca/product-detail/e … ND/1786120
https://www.digikey.ca/product-detail/e … ND/1003189
https://www.digikey.ca/product-detail/e … ND/2180616