Oldham Local Studies and Archives Library holds a full set of Burgess Roll and Electoral Registers going back to 1850 but the complete run covers the town of Oldham only. There are gaps during both World Wars when registers were not published.

Coverage of surrounding districts is good but there are gaps and Royton is not covered for the early 1920s. It is covered for 1851, 1871 - 1915 and 1973 to the present day. Lancashire Record Office in Preston hold registers from 1934 - 1946 but it is an incomplete run.

Local Studies libraries tend to have a small collection of borough or district poll books. The Harris Library, Preston, hold Poll lists for Preston 1807-1868, Burgess Rolls 1844-1864, Electoral registers for much of the 19c.

In the UK these are referred to as Electoral Registers or Electoral Rolls. In earlier times they are often known as Poll Books.

• The electoralregisters.org.uk site offers ... information about the electoral registers, electoral rolls, poll books from 1700 to the present day, how to access the registers online, how to make the most from your searches, what is available and not available, and much, much, more.
• For some of the legal background, this legal volume about The Representation of the People Act, 1918 may prove useful - https://archive.org/details/representationof00frasrich?view=theater

• British Library holds copies of all past and present Electoral Registers for view by personal visit. Their online guide provides details of what is available, both from them and from companies offering paid-for online access. 
• Lists of Names: Pollbooks and Electoral Registers (archived copy), by Stuart A. Raymond.
• Electoral Registers - "information about the electoral registers, electoral rolls, poll books from 1700 to the present day, how to access the registers online, . . ."