[Sir Rooth]

Hello Sir Rooth, welcome to leoforeia.gr!

A lot of municipalities had Ikarus E91 buses but most of them are withdrawn now. You can find some of the municipalities that had such buses in the gallery in the link below:

https://leoforeia.gr/photos/thumbnails.p...n&type=AND

As far as your questions are concerned, I will try to answer as accurate as possible, other members of the forum may add more details or correct my writings:

-I think that the Ikarus 405 of Alimos is not working in reqular lines anymore. In gov.gr though it looks like it has not been withdrawn yet, I think the municipality uses it in special routes but I don't know their schedule.
-Nea Filadelfia has indeed 3 or 4 Ikarus E91 buses and they still use it for regular transportation. I used to live there and in local websites I have not seen any news for new buses or suspension of the bus services, so I conclude that you can see some E91s there. You can find the bus schedule in the link below:
https://dimosfx.gr/%cf%84%ce%b1-%ce%b4%c...%bd%cf%89/
To help you a little bit, the small green bus signs in the picture of the schedule on the lower side of the screen indicate when the bus reaches its start/stop point near Perissos station of line 1, which is the point indicated with a yellow arrow and dot on the image in the wetransfer link below:
https://we.tl/t-MEdIXaHvec

Peristeri municipality also had some Ikarus E91 as you wrote but they are currently replacing their buses with BYD ones. Also it is impossible to find any information about the municipal bus routes, I have never managed to find such information on Peristeri even by giving the municipality a call.

Metamorfossi and Acharnai had some Ikarus E91s but they have withdrawn them. Chalandri had 7 Ikarus E91s but I do not know if they use them anymore. Also Dionysos municipality had some but I know nothing about their fate.

Please keep in mind that generally municipal bus lines are suffering by lack of maintenance and drivers so their schedule may change without notice. Also note that many municipal bus lines do not operate in August.

-As far as Ikarus 260 are concerned I do not know where you can find in dilapidated condition. I think that one or two have been restored though but I don't know where you can find them.

You could also take a look at this topic, you might find it helpful:

https://leoforeia.gr/forum/showthread.php?tid=9073

Thanks for your help!
The Ikarus 405 in Alimos is in operation, not every day, but it is in circulation. 
Unfortunately, the Ikarus 405 in the city of Patras has not been operational since the beginning of July.
The municipality of Nea Filadelfia owns 3 E91s, according to them, 1 is operational. Unfortunately, the municipal service is not operating.
The red E91 of the municipality of Peristeri stands on site, it did not look like it was being used. There was a timetable behind the windscreen, the flight operates from morning until about 16:00.
In the yard of a car service on the outskirts, we found another dismantled E91 bus, in a very incomplete condition. 
Perhaps there was an inscription of the municipality of Metamorfossi on the side of the bus.

Thank you again for the help we could for photographing and we were mostly greeted in a friendly manner!