I think the position of the touchpad (or vectorpad as on ST-Book, Trackpoint on Thinkpads or trackball on Powermac) has to do with the mainly expected operating system to be used on the laptop. These TA-Olivettis came out in a time when MS-DOS still was the most important OS for PC, so user interface was based more on keyboard than mouse. So it maked sense to put the keyboard in the front on these thick devices. In 1992 Windows 3.x just started to get popular. On the other side, Powermac came with graphical UI by default, so it's more logical to place the touchpad in front of the keyboard as the machine mostly is used by mouse. (That's also what I don't like on ATARI ST Book, it has the vector pad in the same position as the TA-Olivetti's touchpad, for righthand users quite Ok, for lefthand use almost impossible, but the vector pad is very important to use that GEM machine.) Later Olivetti Philos 33 (
click had a trackball right of the keyboard, similar to that addon trackball from Logitech wich could be glued to the laptop's side, but Olivett's trackbnall was snapping in and out of the notebooks chassis, very courious and creative. Later Olievtti Echos series first had trackpoint and then later capacitive touchpad in front of the keyboard as they were already designed to run by default under WFW 3.11 and Win 95.