You might have some luck looking for these kinds of items of eBay. Another good source is model railroading shows which pop up from time to time all over the country. You can get a listing of these train shows by doing a Google search or purchasing hobby magazines such as Model Railroader. I can’t say if the type of ‘action’ accessories would still be available as new items any longer. I should mention that these type of accessories are more likely to be found on Lionel or American Flyer trains which aren’t HO scale except for a few items.

Hope this helps,

Geof