If you haven't ordered the samples already, don't. First hand experience of the Aragon and they are a fairly rough texture...... the current batch also has a very slight brown hint to it so I can't see it being a good colour match. (and the round edges are crap). Sorry but had to be honest.
If they are a smooth finish, my money would be on them being either a very old Dorset Black or the Platts Ferrolite 152. If they have a very slight texture, could be worth looking at the Ruabon Black. These will be much closer. What thickness are they, and is 150 the exact measurement?