The current law and regulations do not preclude an antique handgun from being used under the same circumstances as a non-restricted firearm.
I do not think that this was the intent of the government. Anyone really think that the government intended that folks would be carrying loaded revolvers around the countryside?
How long do you think that the current circumstances will last?
I would suggest that if you want to acquire an antique handgun in order to take advantage of the present situation, buy one that will retain value if the rules change. Antiques that have been altered lose value relative to those that are original, from a collector's perspective.