a standard gt reverso duo in gold (hence 1.54.. mine in steel is 8.54, rose gold seems to be 2.54). 25x case prefix is traditional classique. Later ones should have the 1000hrs and fish logo to rear of cradle, and pusher that isn’t recessed, along with round sub seconds (think I’m recalling that rig
My old e159 had the snap back, and fabrique en Suisse (white dial) - the screw backs seem a bit less common - there was one extraordinary example of a shom with a screw back at artcurial (I think it was) a couple of years back. ...?
.. I recall seeing a modern small seconds classique sized reverso a couple of years ago fs at a reputable German dealer - the reference code I saved from then was 252.8.54 .. not seen another since. That option was mentioned in the post-harmonisation done immediately they went from 250.8.86 to 252.8
.. If the vendor uses either of the apparently magic terms sei/tre tacche, that seems to be a license for the price to head off to the moon, on some of the usual sites.. thankfully not all private vendors seem to use that terminology and without those, decidedly cheap, and huge character .. longines