I have White's XLT that I bought in 2002, vert trusty. Lot's of Colonials including Civil War Era . Check this out :
I found this relic this past Saturday.. I see you also have one. I currently use the Minelab Vanquish 440. I have 2 other detectors.. Whites Classic 5ID, Minleab CTX3030.
Nice ! I tried detecting the beach with it . No luck. Too much mineralization . Found a fat Donut / coffee waiting for me afterwards ! lol.
I've got 2 XLTs, a Spectrum and an E Series. Started dectecting back when with a Whites Silver Eagle.
I love the XLT ( user friendly ) . Minor programming that's it. I have former friends who own DFX's and Minelab's.
Yes, Longacre doubling . If you are unfamiliar with it, google it. For coins of that era, a different method of die formation. http://www.numissociety.com/content.php?135-Longacre-Doubling-A-discussion http://www.error-ref.com/longacre-s-doubling/