ve7xen I actually just did that before refreshing this page and reading your post! Earlier I read
ade's reply and I knew trying to get the password from the original supplies of the phones would be a long shot but I decided to look through the phone's menu's once again for any details and I saw the provisioning server url in the Status menu so I set everything up DNS wise etc and a correctly named .xml file with a password of 0000, the phone provisioned and voilĂ
factory reseted them both!
Thanks everybody for your responses, these phones will be off to my brother in-law now. I will pick up one or two more of these spa50XG series phones for myself and if provisioning doesn't work (these phones are almost always password protected coming from business environments) I will attempt removing the flash memory as a last resort.
Thanks!