18KT GOLD OMEGA GENEVE

I recently aquired this solid 18 kt watch,I was a bit sceptical as there was no back stamp,synonomous with all omegas,,took it to a jeweller and it tested 18kt,the clasp is original omega,but not solid gold,I do need to replace the strap though ,just another myriad of things piling up on my things to do list,but confidant will get there soon,wishfull thinking at present though,