There are a few people with this name in the city directories around 1930, but none labeled cement workers or at this address. No F. Gaulcos in the newspapers, either.
This date is much older than previous Frank Brown marks, but the date is incontrovertible. This part of Millsmont has a bunch of Brown’s marks, so he may have had his address nearby.
I thought I’d seen all the variety to be found in Ed Doty’s marks, but here it looks like for a short time in 1930 he posted the month and day as well as the year.
This block is crowded with Gus Johnson marks from 1930. The majority have the date inside the mark, but many of them have this format, which I think is unique to this year.