They just need to get creative. Could wear the Gold Coast Stingrays jumper from the old under 18’s state competition, that would resonate with a number of supporters of a certain age. I’m sure there are Gold Coast rep jumpers from yesteryear that they could resurrect.From what I understand of the Gold Coast situation, I don't think Southport would be too keen on that arrangement.
Other than that it makes sense.
Pretty sure it was Illawarra in the NBL, that rolled out an old district representation jersey for their heritage round a few years back.