Steel. They stuck to a magnet. The pictures are after a soaking in vinegar overnight and some buffing with the dremel (until the battery on it died). They are now soaking in Ballistol. I would like to reuse them if possible.
The Firebox housing doesn’t need a respray and the heater is functioning. So, I am not going to drill out the rivets on the boiler.
More to come.....