it's a Garrett actuator... part # 1011-673 is the standard/stock boost level - 14 to 20 psig, actuator rod begins to move at about 8 psi.
that welded bracket is a stock compressor cover bracket - stock turbo, TA-49, etc where turbo uses stock cover backplate.
stock covers use outer holes on actuator bracket. with same center to center measurements, looks like someone wanted to "clock" this actuator to use the middle and one outer hole.
I conclude this adaptation was for using this stock actuator for the 86-87 stock and stock appearing turbos on a hot air 84-85 stock turbo or its upgraded TA33 (the same as a TA49 used for 86-87)
the center to center distances are too small for this to be for an e-cover turbo. see those added bracket mods below on link to full throttle...
All of that style actuator is designed to be used with a T04b bolt pattern. For any other bolt spacing/locations the actuator bracket will need to be modified.