For a start it isn't my plane, unfortunately.
Fair enough. In that case you buy an iPad and run some appropriate nav software on it (Foreflight in the US but not sure that exists in the UK), and a nice yoke mount. It's not approved but it has a much smaller chance of flying you into the nearest thunderstorm.
If you're a student then my comment about for-real IFR doesn't really apply. You probably should figure out how to tune the thing, even though it belongs to the era of Buddy Holly and cars with tailfins. Make sure you have a supply of replacement valves for it too. Those ECC88s hate being shaken about.