Stihl 041 AV Fuel/Oil ratios

Have inherited a Stihl 041 AV bought to fell dead elms in 1973! Came with manual and tools. On second chain and original bar. Totally overengineered, no chainbrake. Absolute beast. Manual says 25:1 mix but have heard modern oils allow 50:1. Has anyone any views. They don't make them like this anymore. No bad thing perhaps.......

50/1 with good stihl or husky oil

If you use an oil suitable for mixing at 50:1 then that's what you mix it at irrespective of the machine.

Oils have changed and ratios have changed, the laws of physics regarding lubricating pieces of metal rubbing against each other at high speed haven't so have no qualms about modern oils in an older machine.