There was mugica then suc de j.c. mugica. Both worked from eibar and both went out well before diarm killed alot of the smaller makers. Jose Cruz made some nice sidelocks. Most were lower end boxlocks. Dont think one could ever consider their works as a "best" gun as theyre far below AyA in fit and finish but theyre generally dependable. Avoid any single trigger and ejectors and you shoukd be OK. Value is $300 ish for a good condition boxlock. The siddlocks have to be taken gun by gun
An AyA yeoman or matador would be a safer bet which a well used #4 being even better