Those numbers are definitely hard to cross. If you are really determined to get replacements, I would take them physically out, get a calipers and record the dimensions. You can then use Timkens or skf's online catalog to determine what number they cross too.
To be honest though, if the the original bearings are just fine, I wouldn't change them. Those 1930's bearings are more than likely of high quality.
Owner of former Wisconsin Dells/Lyndon Station Decot Model 12 (10/15 port)
Owner of the world's only fully operational Mobil Directo BN52G