What size screw do I need for Peco surface mounting point motor assembly?
I've not used any PL-11s but Looks like you'll need very small screws. Maybe the track screws sold by Fleischmann?
In videos most people seem to be using track pins rather than screws.
Perhaps these will do the job, but I don't know for sure. Fpund them on ebay along with some other options
https://www.ebay.co.uk/itm/352080986897 (https://www.ebay.co.uk/itm/352080986897)
https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=n+gauge+track+screws&_sacat=180250&_ipg=200&_sop=15 (https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=n+gauge+track+screws&_sacat=180250&_ipg=200&_sop=15)