Repolarisation and level crossing resonance will be studied for several different oxalate compounds where muon radical states are known to be formed. Such compounds form a relatively simple model system, that should be relevant to a broad range of molecular magnets. Both magnetic and non-magnetic oxalates samples will be studied. From detailed analysis of the field dependent polarisation curves as a function of temperature in the non-magnetic, paramagnetic and magnetically ordered states we expect to be able to build up and refine a model for the characteristic coupling of such muon radical states to the magnetic properties of the underlying magnetic system. Such a model will then be very helpful in interpreting data from the wide range of molecular magnetic systems where muoniated molecular radical states are likely to form.