ordnance survey - Easiest way to create historical street maps using QGIS

I want to make some historical street maps using QGIS. I understand how to upload a historical OS map from DigiMaps to QGIS, but I want to actually 'draw' the streets myself in order to have some detailed maps. The area I am dealing with was subject to a slum clearance in the 1960s and I am looking to map it how it was in the late-nineteenth and early-twentieth centuries.

Could anyone offer advice?

Thanks in advance!