score:8
As justCal suggested, the symbol in question is a ligature of Tls, used as a unit of currency, the value of one tael's weight of silver. The Reports on Trade at the Treaty Ports in China for the year 1870 has many instances of un-ligatured "Tls", the word "Taels", the ligatured form of "Tls", all in contexts making it clear they are used synonymously. If you search about in that book for "tls" you will find instances of amounts like "Haikwon Tls. 1,496,293.6.3.8", unligatured, and elsewhere tabulations headed with currency labels, in some places just the ligature, and in other places "Hk. Tls. m.c.c" with Tls ligatured, and figures like "68,873.4.3.7" underneath. The tenth part of a tael is a mace, the 100th part is a candareen and the 1000th part is a cash (see, eg, this); I surmise the m.c.c. refers to these fractions, much as L.s.d. refers to pounds and their fractional parts, shillings and pence in English financial tabulations.