Hi,
Not beeing familiar with JAA regs at all, (atleast not yet) and I asume we are talking a flight under JAA rules I probably shouldn't say anything. But I couldn't resist. Over here in the US (were I fly) as far as I'm conserned a fuel gauge is a required item by FAR 91.205, and hence a inop gauge on a Pa28 would be a no go item.
thats just my two cents.