James, that is a fine collection of insignia you have there. As for their suitability as kilt pins - well, I am not entirely convinced (sorry!). For me, the pin should have some relevance to the kilt to which it is attached unless, that is, it is of a purely ornamental design - but, I am sure you would be able to match some of those with a kilt (I could not!).

Also, I believe you should avoid widespread, or horizontal, designs, such as the wings, as these are so much more likely to become caught on furniture, shrubs and other obstacles we encounter in daily life. In this connection, I find that I even catch my X Marks pins from time to time, and have to be aware of this when wearing them. Vertical pins do tend to be less problematic in my view.

Having said that I, like you, am invariably on the lookout for items that might convert into unusual kilt pins as I am sick to the back teeth with tacky, moulded sword pins, especially those with clan emblems! The few sword pins I have, with one exception, are of sterling silver and were not mass-produced.

Good Luck with your search for something different.