[KWo]

Originally Posted by Aje Wouldn't it work if i add the per map config file with the Official CSDM V2.1? I have put in this file C:\Counter-Strike\cstrike\addons\amxmodx\configs\maps

You need to have there the file called cs_deagle5.cfg with these lines:

csdm_reload "csdm\extraconfigs\items_cs_deagle5.cfg"
mp_freezetime 0
mp_timelimit 0

As You can see these cvars should be here, and the map specyfic configuration You have posted (except these 2 last lines they are already above) should be stored in the file items_cs_deagle5.cfg placed in csdm\extraconfigs folder (this what You have posted with all pistols greyed out except deagle and primary weapon grayed out).
There is also a better solution - instead have all grayed items in the menu You don't need to have them at all except deagle. All You need is this:

[secondary]
deagle Deagle 1

[primary]

[equip]
menus = s

Instead asking if it works with original 2.1 (You should use 2.1.1 if You are using AMX X 1.8.0) just try if it works - it will take You less time than waiting for my reply. It should, but with 2.1 version was a problem with too short path possible for extraconfig files (fixed a bit, but not finally in 2.1.1). In my version it works.