The index of openness of trade policy (average tariff rates; non-tariff barriers; black market exchange rates; the presence of export marketing boards) was originally constructed by Sachs and Warner (1995) for the 1960s to 1980s (available here at Jonathan Temple's Economic Growth Resources website), which has been corrected and extended to the 1990s by Wacziarg and Welch (2003).
Hall and Jones (1999) is among many papers that use the Sachs-Warner index. Wacziarg and Welch's extended version is used by Giavazzi and Tabellini (2005) in their investigation of interactions between economic and political liberalizations.
There's been a debate on how to properly measure trade openness. See Pritchett (1996). Rodriguez and Rodrik (2000) criticize the Sachs-Warner index. Frankel and Romer (1999) create an instrument for the share of exports and imports to GDP, a standard measure of trade openness, based on geographical determinants of trade. This instrument is used by Dollar and Kraay (2002), for example.
UNCTAD-TRAINS database, available from World Bank's World Integrated Trade Solution (WITS), provides time-series data on tariff rates in each country. The data for Indonesia is used by Kis-Katos and Sparrow (2015), for example.
Historical tariff rates since the 19th century until the pre-WWII are made available by Blattman, Clements, and Willamson (2003).