Classic/Antique Car Repair: Fordomatic auto transmission speedometer, ford fairlane, speedometer cable

Question
I have a 55 Ford Fairlane with a fordomatic 2 speed automatic transmission, I removed the speedometer cable to lubricate it and the platic gear that attaches to the end of the cable fell into the housing, I get get my little finger in the hole but can't locate the gear, I put a clean bag in my shop vac a placed on the hole hoping that would get it into the bag or at least get it to where I could fish it out, I have used mirriors and can't locate it.
Can that gear get into the output shaft if I drive the car?, I have other people tell me they have had the same thing happen and they just put their cable back on and forgot it but I'm concerned the gear can cause me trouble later.
Your input would be appreciated.

Answer
Back in that era I worked for Ford as a trainer. The official company line was to remove the tailshaft housing and remove the old gear. That said I would like to have a nickle for every two speed fordomatic that was running around with at least one dropped speedo driven gear floating around in the tail shaft housing. I am not going to tell you which way to go only what I know from personal experience in 1955.
Brad
My 55 Mercury ran a couple of hundred thousand miles with a gear or two floating around in the tail shaft housing. And yes I am that old that I had completed school and was working by 1955.