I've got a load of shots of old houses in a popular UK seaside town, where the house names are clearly visible (see an example below). I have in the past had rejections due to 'intellectual property' reasons, because a house number was visible in the photo. Should I submit these pics as illustrative editorial? I don't want to clone out the house names, as it's an integral part of the building.

You can try, but they will most likely be rejected. Adobe doesn't think non-specific houses are worth submitting as illustrative editorial, because there are enough commercial photos fo houses in their database already.
https://www.microstockgroup.com/fotolia-com/mark-as-illustrative-editorial/msg575515/#msg575515