I want to check the oil level in the gearbox of a 1.3 Felicia.

I seem to recall reading that its possible for the gear to fall off the end of the cable into the gearbox while doing this - Does this apply to the felicia? If so what can I do to prevent this from happening?

You have to remove the speedo cable to get at the level - you check it by looking at the level on the gear for the speedo cable. You need to lift it out the mechanism - not just by yanking on the cable! Its worth getting a haynes manual for a look of how its done.