Should be a #2135 key. It fits all the Micors/Syntors/Maratracs, and so on.
Info below from repeater-builder.com website:
This is the Motorola mobile key, price is $2.04 from Moto (early 2006). It fits almost all of the key-lock mobile equipment made since the mid-1960s - the pre-Motrac tube-type mobiles in 10" wide housings (e.g. the GGV / GGT series), the Motrac, Motran, Mocoms, Business Dispatchers, Micor, Mitrek, etc. It also fits some of smaller base station cabinets - Consolette Stations (table top base stations), "Compa Stations" (compact floor mount cabinets) and more. This key also fits some in-building wheelchair lift key locks, as well as the daily / sunday price change control on some newspaper racks. Any Motorola 2-way radio shop that advertises in your local Yellow Pages probably has a bunch of these lying in a desk drawer somewhere - Moto shipped two with every mobile radio and usually the radio shop installers kept them (sometimes they gave one to the vehicle owner, but not always). If you can't find one from a Moto dealer you might check your local Yellow Pages for a local dealer of Toro brand commercial irrigation equipment (i.e. golf courses, city parks, vineyards, orchards, commercial nurserys, etc) - this key also fits some of their equipment cabinets.
