Please don't take this as definitive, but I was under the impression that all logbook entries (in CAA world at least) were accepted on the "honour" system.
Current CAA guidance says that computerised printouts are acceptable, providing each sheet is signed by the "logbook" owner alongside the statement "I certify that the entries in this logbook are true". (or similar).
It is not necessary for a CAA instructor or examiner to sign your logbook for any licence, rating, renewal or revalidation. The forms which are sent to the CAA are sufficient. FAA is a bit different, since the logbook "signoffs" provide the only evidence of your currency - unlike the JAA licence which has the relevant pages.
Back in CAA land, the only co-signature which I am aware of is that required for PICUS or P1/S. (Something the FAA don't recognise). However, you can still log the total flight time so long as the PIC is declared.
I think the difficulty may arise in justifying the time in the P1 column without the PIC's signature, but again I think that it only becomes an issue should there ever be a dispute.
I am also aware that the total hours claimed can be accepted by the CAA for a "lost" logbook - without trying to re-create the original. In this case, you simply have to produce a sworn affidavit.
Obviously, there is scope for abuse of the system - and it has happened in the past. But the CAA aren't stupid, and if you went for an ATPL on the basis of a 1500 hour affidavit - then you can bet your history and training would be scrutinised.
So, in summary, I am pretty confident that you could copy your logbook over to a new book without penalty, providing you sign each page. (If it comes to it, don't use tipex though. Just draw a line through the error, write the correction next to the deletion and initial it.)
Hope this helps.