ruddy hell that bike was a bargain, nice to have the original specced cranks and chain tensioner
thats a 1997 model, all you need to run a front mech is the little plastic runner that fits to the underside of the bb tube. all the bosses should be there on the down tube?
it has a spring tensioned bottom runner, the spring is steel and corrodeds badly, easily replacable, i doubt anything else is wrong, the ac device is pretty tuff, and pretty.
These pics were taken a while ago but bike is pretty much the same, has a temporary Fox shock in place of the Rock Shock, fitted a nice XT rear mech to replace that manky modern Deore thing, thumbie is now on the left hand side under the bars, bars are painted to match the forks and i've got a red flite to go on it, also using the 40T outer ring now instead of it being redundant in these pics, my frame has never had a front mech fitted, you can use a top swing or an E-type on them though
I have the same early Z1's as you with the twin caliper mounts.