#440 Or #477? Watermark

I'm gathering together some stamps to sell on the internet and I've IDed these two 50 cent Franklins as either 440 or 477. I understand that the only way to really know is to find a watermark.

Could anyone advise the best way to list these 2 stamps without IDing a watermark? I'm new to selling on-line too...so I'm concerned with listing these stamps with the proper info and condition so there is no misunderstanding.

It is not possible to tell SC440 and SC477 apart without checking the watermark. To do that you need a tray and some fluid. Even then the single-line WMK can be difficult to discern. When you get the bottom stamp in the fluid, any creasing faults will also become more apparent.