Some nice pics mate, good to see you enjoying it. So, the ATF change cured the slipping when changing? Unfortunately it's the only thing you can do to a Honda auto, no adjustments, don't think there's even a filter can be changed, never seen one or where you could get to one. Makes you wonder why an aftermarket in-line one in the cooling lines to the radiator has never been available. Sometimes the fluid change can do wonders.
Does your trans have the "lock-up" feature that the B20a versions had? The torque converter has an internal clutch, I believe, that engages above certain road speeds to provide a solid connection through the trans.
I was looking on this page at the gear ratio differences between the B18a and B20a automatics and the smaller engine was higher ratio/lower speed in 2, 3 and 4th stages, but with the same ratio diff and 1st.
http://www.hondaoldies.de/Korbmacher...d/tdacc3wg.htm