Gordon, that relay latches electrically with the diode that is shown in Ray's picture of the relay schematic.
Carey's(and Leon's) idea is most probably your best bet.
Carlos, I know you like to fabricate. I got the smallest momentary pushbutton switch I could find, and machined a couple pieces on my friend's lathe. The stainless tube allowed 2 skinny wires(RC servo wire) to go through and connect it. Cheers!