what do i have here

View attachment 1715611443 View attachment 1715611444



i got this 340 years ago probably 25 or so its casting date is 8 18 68 and the timing tab is on the opposite side . i just noticed it does not have a harmonic balancer as you can see . is this how the early 340's were made ? it also has no vin stamped on it .
Does the pulley have some rubber sandwiched in it? maybe it's meant for harmonics too?