Need a better step detection algorithm
This is an interesting problem.  I've downloaded your data and written a small program to process it.  

There are missing data points that don't seem to be correlated with the jumps.

It seems to me the best approach is to look for matching jump values and adjust the values in between.  The first step was to measure the RMS of the jumps from point to point to gauge the typical jump size.  Next, I identified the jumps that exceed four times the RMS.

These are the results:


The Jump RMS = 1.270752

1262310195, -29.989300 Down
1262310259, 30.380400 Up
1262310355, -7.228400 Down
1262310364, 5.666300 Up
1262310438, 6.014400 Up
1262311415, 30.857000 Up
1262311626, -14.630000 Down
1262311627, -15.643500 Down
1262312656, -16.754800 Down
1262312657, -10.732500 Down
1262312859, 29.599500 Up
1262313801, 5.085400 Up
1262314529, 31.463000 Up
1262314694, -30.519800 Down
1262316412, -29.813200 Down
1262316483, 29.996800 Up
1262316604, -5.110200 Down
1262316612, -5.084100 Down
1262316614, 8.913200 Up
1262316618, -10.073700 Down
1262316620, 10.929100 Up
1262316621, 6.930200 Up
1262316623, -5.136700 Down
1262316624, 8.932800 Up
1262316625, -6.066600 Down
1262316628, 17.934800 Up
1262316630, -7.129600 Down
1262316631, -11.064500 Down
1262316659, 6.889600 Up
1262316661, -5.111200 Down
1262316663, -8.125000 Down
1262316665, 11.254100 Up
1262316667, -9.666300 Down
1262316668, 6.854200 Up
1262316680, -7.209700 Down
1262316689, -7.270200 Down
1262317545, 29.889600 Up
1262317785, -29.615400 Down
1262318838, -17.595400 Down
1262318839, -12.571100 Down
1262319054, 29.935400 Up
1262319539, -17.311700 Down
1262319540, -11.272300 Down
1262319567, 30.747600 Up
1262320679, 30.134800 Up
1262320869, -30.649600 Down
1262322664, -29.883400 Down
1262322703, 30.569600 Up
1262323699, 29.895000 Up
1262323975, -29.298600 Down
1262325018, -17.261100 Down
1262325019, -11.246300 Down
1262325269, 15.262600 Up
1262325270, 13.273800 Up
1262326865, 30.136500 Up
1262327071, -29.004400 Down



It looks like now it is just a matter of matching up and down swings.  There is a wrinkle in that it appears that some of the jumps in the same direction are adjacent, so it takes two data points to make the jump.

Another wrinkle is when the jumps are matched, the values are quite exactly the same, so coming up with a formula for the proper rectifying shift is another puzzle.

Anyway, send me an email to cedron at protonmail dot com and I will send you the source code so far, and maybe take further yet.

Ced