Great job so far, i did the BlueCrystal skin (with help thanks again Thom and Karel)
Did you already set a database administration tool up? (i use MySQL Workbench)
In there you can find a table under the main tree that is called 'icon'
In there you can see the column 'MainFileName' which shows you the icon's name and path.
Also a column 'Description' which basically shows you what it does
If you want a specific icon to show on the orbiter, you must make a icon for it and save it in the path and with the name shown in the column 'MainFileName'
If you have any questions just ask, i am glad to help