For the clock, get the bulb out, then go to your local auto parts store. You may or may not see any lettering on on the glass. If no markings, compare it against the ones at the store, paying attention to size, shape, and the way it's socket is designed.
Gonna assume it's 12v. Just be careful not to get anything too big to fit and make sure it's not touching anything. Non LED bulbs (regardless of size) can get HOT and have the ability to melt things. Once had one of those TINY bulbs in an ash tray surround and it was loose and melted some carpet (under the ash tray in a center console, forget which car). Unsure if wattage is listed on the small bulbs or not. If the packaging lists it, go with a lower wattage 1st. See if it's bright enough. Other option is to convert to an LED bulb. If bulb is too large, but at least directional, you might be able to monkey it up in a way that it "aims" the light into the opening of the stock bulb. Doing this might allow for a much brighter back light to the clock w/o the added heat/danger from a standard bulb. And to drive the heat issue further, the bulbs that are the size of an eraser get hot enough to melt plastic or cause skin burns.
The "D" indicator might not be bad. Get access to the bulb, and try swapping it with another one from the same area. If it's still dead, just use it as a reference. Most of the bulbs in that size range are fairly similar to each other.
About the best I can help with w/o a Haynes manual on hand. Other option is you can try and call Ford's service dept. and ask them "if they can tell you the bulb numbers" and "how much it'd be to order them". They should be able to give you the bulb number, then just say you'll hold off on ordering.
