'An engine is described as oversquare if its cylinders have a greater bore diameter than its stroke length'
the 1.6 in the 145/6 is 1596cc as opposed to 1495cc - 1.5l, or 1712cc - 1.7l. Possibly a factory mixing of crank and pistons from the 1.5 and 1.7 to make a 1.6. (?)
the 1.5 mech tappet made 105 HP standard, and the 1.5 IE 33 made 11 HP standard, so think it's fair to assume the 1.6 will mek a little more.
the 145/6 was heavier than 33, so some attempts were made to wring a little more HP out of the boxer before they went TS...
once there were lambda sensors in the cars tho, HP figures all got a bit vague with many regional variations..