Swan 1040 V Trap Vertical

Hello,

Wondering if anyone can explain to me how to grid-dip trap coils to
determine which coil is for which band to be used in the 10 thru 40
meter 1/4 wave trap vertical originally made by Swan. The antenna was
completely disassembled and, since it is so old, the markings on the
metal sleeves of each trap has weathered away. For me, it would be
much easier to dip the traps to determine the frequency rather than
climb up on the roof to do the cut-and-try method for each band (small
back yard, no room to ground-mount the antenna).

Any help greatly appreciated. Thank you,

Tim Watkins
W6WQA