Success!
Thanks again for everyone's help; Jh for keeping the mind active.
G, I am using iFiles and iBooks within their limits. iFiles is good for capturing text, cut and paste, and allows direct PDF output via 'send a copy' - Acrobat . iBooks enables PDF copy of web pages, then email to self for use in Acrobat.
le Pingouin, yessss !
The File Explorer App has the option to add (+) an external location.
Western Digital was in the menu - the hard drive which was connected as a 'NAS'. However, by choosing the NAS option and thence via the BT Hub to the usb1 option, all files on the hard drive can be accessed (no login or system address required). So far some files can be saved back to the hard drive from the iPad via iFiles, Acrobat, and PowerPoint.
The add location option appears to be restricted to a one off use, or limited locations where many are provided - a range of NAS's. An upgrade to the pro version offers unlimited access . So far so good, even if my set up is a time limited system, the pro option provides many opportunities.