Are you sure this is what you get over the wire?
0000 33 37 34 36 32 32 34 34 31 37 31 35 31 30 31 31 3746224417151011
0010 37 35 44 32 36 30 37 31 33 36 31 39 31 36 39 39 75D2607136191699
0020 33 39 39 39 39 39 39 46 3999999F
It seems to me you are converting it to HEX and then using IFA_LLBINARY. If you use the raw data and then use IFB_LLNUM, jPOS would take care of that extra ‘F’ padding for you.