One Choc Coloured after ripened Plum sized Tomato plant sprung up all on its lonesome not too far back and let it do its own thing and this Tomato has come up trumps in flavour for me at least and dont know if its because im getting a tad on in years or what lol but cannot remember when i grew it prior or its name/variety??.
But kept seed as it did tickle my taste buds and the plant is growing like crazy with nothing standing in its way regarding disease or pests!!..

It could well be a crossed seed from a past years garden. Grow a few of them again next year and see if you get an identical plants or if you get something else. If you get a variety of tomatoes then you will know that it was a crossed seed. Then you can try to stabilize it and make it your own new variety.

The disease and pest resistance is a huge plus!

Thank you MissS and have a fair idea it may have been part of last years plantout?? , though not sure but have kept seed and will re sow just to make sure .
Although i mainly grow the Cherry Variety for the Grandchildren to freely pick whenever they come over this particular fruit i liked, especially when you dont have to worry about the plant so much regarding disease etc.
Here locally its a game of cat n Mouse trying to keep Plants healthy and green so its a bonus when you get some that dont take much looking after except feed and water ey..