1973 - Ithaca Model 37 Featherlight
What is the condition of the gun and the barrel length?
Your Model 37 was mfg. in 1975.
From a recent internet search, a 16 gauge fetches roughly $385.
I am not sure if the date makes a huge difference, but GunBroker.com says the featherlight is worth and estimated $375.00.
You will need to contact Ithaca. Published sn's do not go that high.
Depends entirely on age and condition - neither of which is indicated in the question, so no way to answer.
Yes, they did make a 28 guage pump featherlight. I have one myself
Depends on the model and condition. An Ithaca Mdl 37 Featherlight in 16 g in excellent condition is $500-$600 at retail.