There are a couple of races over the Easter weekend which you might want to consider as Grand Prix races.
Good Friday there is the Calder Vale 10m race which I did a couple of years ago and is well worth doing. You may still be able to enter online, however you can enter on the day for £2 extra. Race starts at 1pm.
Easter Sunday there is the local Runcorn Bridge 5m race which again you may still be able to enter online. There are limited entries on the day before 08:30. The race starts at 9:30. If I recall correctly this is a course to set a good time.
I am considering doing Calder Vale.
Remember Chorley night race series starts next month.