Hi Nicholas and Vanessa. Well, unless both parents were purebred too, the offspring is per definition mixed breed. You can read more in the article 'What Breed is My Cat'.
That said, the square muzzle, big paws, general size and of course semi-longhair fur are typical Main Coon features, so quite likely he has more than a just teaspoon of MC in his mix. He could be fullbred for that matter, but without knowing his background you'll can't say.
You could call Franklin a 'Main Coon look-alike', but I think he is best described as a 'brown mackerel tabby mixed bred semi-longhair'.
Most cats don't carry papers with them and are no lesser cats for that. In fact mixed breeds are generally healthier and live longer than purebred. And they are just as loved by their humans. Your Franklin looks happy and at ease, so I reckon that goes for him too. 😉

Franklin is between 8-10 years old and maybe a cross bread any ideas please let me know

He is a good looking cat. Being a Maine Coon, his weight appears to be representative to his size.Did you mention his age. He may get even bigger.I have a tabby (Mackeral) cat that weighs in at 30 plus pounds. However he is huge in size (over three feet long)which allots for his weight.

Hi Nicholas and Vanessa. This is a real great photo - I too would like to see and read more about him. 🙂

Franklin looks very impressive. He must eat like a horse! Mind you Maine Coons are usually rangy, long and thin.

Thanks for sharing. If you have some more pics email me and I'll upload them.