CassiniMaps have now got downloadable old maps without their watermark across them (as yet!)
Go to the website ---> downloadable maps on left hand menu ----> Enter Ferndale, Rhondda ------> centre Ferndale on the map that comes up -----> click on choose map type -----> wait for a new map to load. If it is showing the wrong area you go back to the main map by clicking 'back' and move the map a little. When you've got the right area you want click on 'view map centre for a zoom in. On this same page use the drop down menu to see other scales and different age maps.
If you've got suitable software you can spend a while saving each zoomed in map and piecing them together.
Or you can spend money as they really want you to do.
Sheila