Okay, carried out the above refitting whilst checking B1 part number below.
This number is very different from the actual part order number, 126 270 02 35 on EPC - that said, I can now ask friendly MB parts person to check once arrived and compare, no hit and miss removing the tranny and ATF.
Whilst under there I removed the modulator cap which looks like this:
Not sure if those little teeth are there to lock the T bar pin underneath or it adjusts the pin without removal - any ideas?
Anyway, I turned it a 1/4 turn to the left to see if it would help soften the shifts, bit annoyed at myself as I should taken the car for a test drive first to see if K1,K2 change worked by itself.
The end result however was a big improvement, no flare or hard shift on 2-3 or 3-4 very smooth, although still need to stop myself backing off the peddle anticipating flare.
1-2 shift greatly improved but still there, the improvement could be the modulator quarter turn with the underlying issue (B1 still present).
My thoughts are that if K1, K2 were worn out B1 is probably too, hence no dramatic improvement as with other shifts.
Is it correct to think the modulator only affects the hardness of the shift, not flare?
On another note, bearings and kits have arrived - will post up a bit later on that (all looks good so far).