Installing Leopard in target mode from Catalina

I have two working instalments of Catalina and I have a an old Power book G4 12 inch that I need to install a new OS on. As far as I can understand the latest OS I can install is Leopard (10.5) and I had one old dmg that I used many years ago to install from and I have also downloaded from different repositories online that has old OS versions. I've tried to install from several different USB keys but the computer fails to recognise it as a start up option, not when booting holding down alt key and selecting it as a startup option (with it doesn't see it as) My last try to do it with was to do it as a target mode from my one of my Catalina machines where I have a firewire card but will that at all be possible. Am I wrong in the assumption in that Catalina can only do guid formats and will it even recognise the Leopard OS since its 32 and not a 64 OS. Does anyone know of anyway I can do this or a smart workaround for this. Thank you in advance. Karl