Well I haven't worked again on them, if the new version of Core is released, I'll propably continue working on it. Another problem is to find good pictures of ships, because the Core team changed the model names to quite rare ones I think (an old monitor ship for example).
@ mikwarleo
At first: I use Photoshop, but you can use every programm, even MS Paint.
The way how to convert icons heaviely depends on if you are working on land or naval/air force icons. With the latter ones you will unavoidable encouter serious problems, because Core has units and unit names that just don't exist in vanilla HOI2 and so don't exist in any vanilla icon pack, one example are the torpedoe boats.
But I'll begin with the easier topic: land units.
If I remember right I copied all Core icons into seperate folders (one time for the German models, one time for the Soviet models, etc). If I remember correctly there are only German icons in Ostheim's pack, so one copy is enough.
Then you should have one folder (let's say you called it GER) with all files in it (model_0_0.bmp, model_0_1.bmp,...,model_11_9.bmp). Rename all files by writing "ger_" infront of the names (eg.: ger_model_0_0.bmp).
Then analyse the icons: model_x_0 to model_x_4 are the ones with 6bn, model_x_5 to , model_x_9 are the ones with 9bn. There some irregularities for tanks and mot.inf., but you'll figure them out yourself.
Then you can start converting the models you want. You'll propably begin with Infantry. Model_0_0.bmp is in Core an Infantry Div. from 1930 with 6 battallions. Germany has 9 battallions, so you can delete model_0_0 to model_0_4, aswell as every other model from 0-4 and the model_4_x series (actually you can that before renaming the models). Some SS-Divisions will be 6bn, so be carefull (early LSSAH eg).
The rest should be clear: Select the model you want to have in the end and copy it over it's corresponding Core icon in your programm, overwrite the year number and replace it with one you like and don't forget the 6bn/9bn icon, which you can get from other Core icons. Maybe you will have to use some icons twice, e.g. when the 1918 vanilla-model shows a man with spike helmet and MG08/15 you shouldn't use for 1930.
Ask, if something is still unclear
