743 Lincoln Avenue, Alameda
I’m going to put up a bunch of stamps I collected in Alameda last month. As always, I only use non-Oakland stamps to document dates that I haven’t found in Oakland. Alameda has stamps from a lot of sidewalk makers who don’t appear in Oakland. One reason, especially in the old days, is that the city required a $200 bond in order to do business, which kept a lot of artisans away and reserved street work for the already successful and/or well connected.
LaPlant marks are scarce in Oakland. I expect to find quite a few more dates in Alameda.
Oakland Underfoot 
9 September 2023 at 6:20 pm
As you suspected, there are loads of Alex LaPlant stamps in Alameda, nearly all of them on curbs. Ones I’ve seen date from 1917 to the mid-1920s.
A curiosity is that I’ve found several of these stamps in various parts of Alameda is a year marking of “192_” where the last number is an upside-down “2”. There are enough of them that it could not have been an error – it was clearly done intentionally. I’m guessing the upside-down “2” may have been substituted for a “5” – perhaps they had no “5” numeral to use on their stamps for some reason – and that the year would be 1925.