I am sure that DOT 5 was used. I'll say, however, even though you recommend not to use DOT 5, the m.c. is 10 years old and it looks brand new having been exclusively run on DOT 5. There is almost no particulate matter at the bottom of the m.c. res. and the fluid that I drained out of the old system was extremely clean considering the 142 was a daily driver in Connecticut, where I live. The fellow who owned the car swore by DOT 5 and I'm going to have to go with it just based on the brake systems of the 3 140's he ownes and how long and well the systems worked before regular maintenance. Now that I think about it, I might as well put on his calipers, then I don't have to worry about my crusty ones acting up.