I believe your half dollar would be the CONECA listed 71D DDO-006 (FS-102). There are only two in the listings that have the four serifs on the lower I of IN, like you have pictured, the DDO-006 and the DDO-017. The doubling on yours looks like the DDO-006. A marker I use for my collection for the DDO-006 is the short die gouge above the first T in TRUST, see attached photo. James Wiles doesn't list any markers, but you can see it in his photo on Variety Vista.
