I have that now. Last week I deleted or disabled everything I was not using. All I see now is the rolling stock and locos I want to use. I did the same with every item...routes, houses, etc. It took awhile and now and then I deleted assets that I needed, but that was easy enough to take care of. I am only interested in North American items. I use some "European" vehicles and some great looking "people and animals". If I look under "installed" there are 19,197 items. My route uses 1,710. I believe about 90% of the 19,197 installed items (could note delete them) have been disabled. I'm sure there is an easier way. I'm retired and had a lot of free time last week!
Cheers....Rick
"I'm sure there is an easier way".....see above!