2N5109 and FD700
These parts are practically sure to be obsolete. So your best bet is to look at the characteristics, and get something similar. Look at the circuit diagram, and decide how critical the use is. The main thing to check is the maximum voltage and current. The 2N5109 was a standard Motorola medium power high frequency. Try 2N3866 or BFW16 and your machine at least will be working. The FD700 is a very old Fairchild, now National, ultrafast signal or computer diode. Is it from a fast pulse generator? Try 1N914/1N4148, or Mullard/Philips BAW62, all slower, or a shottky, but they are usually low voltage, though Philips BAT81 series would be comparable, if voltage rating is the critical rating for the circuit. Have a look in your junk box, or raid an old TV unit up for recycling. Bill.