i believe you may need to have something made up.
Though there are a couple fiesta's that came with equal length shafts i think they're all newer mk3 shapes and newer.
You could try measuring up for the newer bits though as mk2's had BC gearbox which is direct swap for IB5 used in newer fiestas. Its the bracket that bolts to block on drivers side that needs to be right, you might have to modify it/make a new one if shafts are right length.
'89 Series 2 RS Turbo 90 Spec - the one for fun: Newman Cam kit, Stage 2 T3, Airtec front mount, Mongoose, Disc conversion, Koni's, Polybushed and Immaculate.
'88 XR3i Cab - project: Custom ITB's, Manifolds & Blacktop conversion, IB5, Group N gear set etc etc... Need to get on with it!