You could fit a longer tube but the price doesn't warrant the work.Could you just fit a longer tube through the middle for the main fuel tank supply? Probably have to drill a hole in the top of the filter, but omn the main tank maybe the silt at the bottom wouldn't get in? Or is it poss to buy the longer tube and filters? Only time I noted the reserve on the SF1 I seem to recall doing 30 miles (50km) and reached the servo, so no idea what was left. Princes Hwy heading north and refuelling at Genoa ... very apt name - wonder if Oz has a Breganze somewhere?!
The current replica taps probably give you twenty kilometres reserve.
Paul