Looks like a Franken Mower made of the following.....
Sycamore 19" deck - I don't know who made the Sycamore lawn mowers, except that a friend had one. They seemed to have been made between 1984 and 1990, and sold at Sears as a budget model small-width mower. That is definatley not the original handle, Sycamore used an hour-glass shaped handle with a zone control on it.
Briggs 80902 or 90902 series engine. 3 or 3.5 HP, System 2 Safety Control, looks like a franken-engine given the multiple colors (white parts). Could have been the original engine paired with replacements from a donor engine.
The handle looks like it came off of something made by Southland mower Corp of Selma Alabama. They made mowers under the name Southland, Vulcan, and Harts Pride, and were sold at West and Lowes back in the day.
The wheels are also not original, they look like the garden variety plastic wheels found on 20" 3.5 HP Push mowers in the 80's and 90's. Sycamore used wheels like those found on Weber and Aussie branded charcoal grills, full plastic, black, and with "whitewalls"
Hopefully I've been helpful here.