DE,
Do the following to save your heirloom tomato seeds.
Take one of the best friuts and cut in half and save the top half and have a BLT or whatever with the bottom. Remove the seeds from the tomato top into a pint size jar with some pure water. Cover with a plastic wrap and keep the wrap in place with a rubber band. Then poke many holes in the plastic wrap and place in the sun to ferment for a week or two.
The fermentation removes the gel sacs surrounding the tomato seed. Scoop everything that is floating and discard. Strain the seeds that are left using a fine mesh strainer and rinse well. Then dump them on a paper towel or newspaper and try to seperate them so they do not dry in clumps. Once dried I put mine in a small paper envelope and write the name and year on the envelope and store in a cool dry place. I started some Kellogs Breakfast from 2015 seeds this year and ALL of them germinated. Your hybrid might produce one or both of the parent strains yet odds are slim it replicates what you remember.
This year I have the Yellow Pear for the 1st time along with Black Krim, Paul Robeson, Cherokee Purple, Mortgage Lifter, German Johnson, Mr Stripey, Rutgers and the Kellogs Breakfast. The Paul Robesons are my favorite and the Black Krim is a close second.
GOOD LUCK.
Stay safe - stay FREE!!!
PEACE
Hydro_gen