Totally agreed, this 080672-- it could be anything. It certainly looks to me like a dob. And yeah, he might be doing the UK format Here's another thing, though.
He was using this as a dob for himself. Now, it may be a victim's dob, maybe a Jane or John Doe without a report where we don't know the dob, maybe someone missing, unreported, and her remains are undiscovered. But it could also be a date of victim death. To be honest, I'd think that's just as likely. And if that's the case, the 08 and 06 would be the date of death, but again, he is using this as his own dob. If he killed the victim on August 6, 2009, for example, he can't list "09" as a believable year of birth for himself. So I'm also kind of staying alert to victims with date of death or disappearance near/around August 6 period. The '72 may just have been an accommodation of his "need" at the time for a believable lie on his dob.