You are right, in Italy, VFR approach charts are published by ENAV for major airports only (you could get them georeferenced for free using Airmate app). For small airfields and ultralight bases, the main source is Avioportolano but it is a commercial source. There is no free information source to the best of my knowledge.
In France, the source you quote SIA Service de l'Information Aéronautique is indeed the right one for all airfields having an ICAO code assigned. In addition, you have more than 700 ultralight airfields having numeric codes assigned by the ULM Federation (such LF8357 for Pampelonne). You could find for them free information and charts on FFPULM BASULM site.