Nath on this particular series it is more likely to be a head gasket.
But you are right that the OP it is better just off replacing the engine.when it comes to this amount of damage. Plus as you parts are hard to come by from Briggs right now. Even here in the states some parts from Briggs is taking months to get. The camshaft have been on back ordered for over two months and it took me over a month just to get governor/oil slinger that fit this engine. I currently having to install lousy after market camshafts because customers are needing their mowers.
