So came up with an idea to improve my heater to a more modern standard rather than just "a bit" and "full blast" (which is a lil weak compared to my old one)
Plan is to fit s 12v bilge blower after the LR blower to force more air in, wired into the LR blower controls for easy control.
Then fit
this (lil more research needed tho) so I can have a smoother more variable control of the fan speed.
Will of course check and adjust if needed the current heater controls.
Final addition is the the Defender vent2.0 which I got for a very good price. Should mean i can adjust the top vents more and should have demisted side windows!