Oddy, there is a min bet of £50 on each race so for now I've assumed that you just piled what was left on Maybe and adjusted as follows:
3:15 NWM 388.89 win Maybe
3:50 NWM 25 EW Cheveton
Is that OK?

Balance £544.44
2.05 Nwm 70e/w Colinca's Lad
2.20 Sals 50 win Royal Perculiar
2.35 Nwm 120win Timepiece
3.10 Nwm 70ew The Fugue
3.50 Nwm 48ew Jarrow
Balance left over £0.44