Yes CRP 1 better for PPL work as the speed scale is more accurate for low speed flying. In fact i used it for the ATPL's some 20 odd years ago, could never understand why peeps spent money on the CRP5.
Previous to that i made one out of a card board box, think it was the Revell Boeing 727 plastic kit box, nice thick cardboard!
Just photo copy a CRP and do a Blue Peter job.