If you're flying from/to anywhere in Dorset i.e. Bournemouth, there's already an online working GAR that's approved by the authorities.
Link here:
Airtime Charters - Complete ALL details as with paper GAR then click SUBMIT GAR FORM at the bottom of the page - CAUTION - This form is for DORSET County use ONLY | Airtime Charters
I've been using it for a couple of months now without any problems. I understand it's likely to be rolled out to accomodate the whole country soon
On a separate issue, IO540 - you can check your AFPEX flight plan has gone into the system ok. As you say, you should not put your own address in but once it has been sent you can do an RQP (request flight plan), just enter the callsign, departure aerodrome and destination and the AFPEX system will return the registered flight plan to you (assuming it IS in the system).