Trying to figure out what series replacements I need

Thanks for posting. We have two balances that closely matches with yours: our Series 351 and Series 390. The difference between these two balances lie within the depth of the bottom balance shoe. The depth of the bottom balance shoe for the Series 351 measures 1" and for the Series 390, 1-1/8". You will need to measure the depth of your bottom shoe, like in the diagram below, to determine which balance would make the best match. For the balance marked with "16 2", either the S351-17 or S390-17 with a 1620 option. As for the balances marked with "28 3", "28 4", and "28 2", either our S351-29 or S390-29 with a 2830, 2840, and 2820 options would work. 

Comparison of 15-001 & 15-002