www.romaheritage.co.uk/parish-records
From the BMD records, if you place ‘draper’ in the Filter Text there are 39 records from 1709 to 1861. Most are Baptisms, 7 Burials and 2 Marriages.
There is only Elizabeth Rainbow bp. Aug 26, 1827 at Clifton Reynes, Buckinghamshire.
For Webb, there are 5 Baptism records from 1699 to 1841
Their Census records has one Draper family of 3 individuals on the 1871 census in Ruislip, London.
All of these records are recorded as travellers.
Added: Newspaper article: 3rd April 1782, George and Charles Draper were executed. There is nothing on their database for Rainbow or Webb.