Hi,
It is possible to use a TRS2006 SP1 map in TRS2004
As an example what i did afther some mails why i build my route in TRS2006 and not in TRS2004 i tryed alot of things
What you need to do is to open the 2006 kuid with the content dispatcher from the TRS2004 programm. Afther that you need to go to the map : world dispatcher/downloads and look afther the map with the kuid no. of the map.
Open this map and change the configfile, add the line asset filename and remame all the other files (gnd, obs etc)in the same map as where you can find the configfile from mapfile to the name of the map and you are ready to go. Only disadvantage you have is that you will miss all the inbuild content from TRS2006(like the PTP content).
region <kuid:149301:1003>
category-class "YM"
category-region "FR"
category-era "2000s"
carrate 0
kuid <kuid:46410:1001>
username "Fictive Paris(Gare du Nord)"
asset-filename "Fictive Paris(Gare du Nord)"
workingscale 0
workingunits 0
water <kuid:-1:6342>
description "Fictive route based on the Gare du Nord area"
trainz-build 2.4
the config file need to look like that for TRS2004
and rename all the other files in de same map from mapfile to Fictive Paris(Gare du Nord).gnd etc.
========================================================

region <kuid:149301:1003>
category-class "YM"
category-region "FR"
category-era "2000s"
carrate 0
kuid <kuid:46410:1001>
kind "map"
username "Fictive Paris(Gare du Nord)"
workingscale 0
workingunits 0
water <kuid:-1:6342>
description "Fictive route based on the Gare du Nord area"
trainz-build 2.5
world-origin {
this is the configfile for the same map in TRS2006
This map is build for TRS2006 and you can find on DLS but as you can see in the picture i also run this in TRS2004
But as told before you wil mis all the inbuild TRS2006content .
I think this is possible with all 2006 maps.
Greetz laika
P.S sorry this has nothing to do with this Thread so sorry for that one.
I'm sorry, but the good news is I think I downloaded the unit you like (the one in the screenie), from 
