I've been looking to buy a Fin Nor offshore spinning reel, and the size/line capacity that I want is their 4500 series.

The question I have is whether the Fin Nor OF45 is the same thing as the Fin Nor 4500, or whether one is a cheaper knock-off of the other. On the Fin Nor website, I can't even find the OF45 (which is what I see listed on various Amazon and ebay vendors), so I'm wondering whether they are one and the same before I go ahead and make the purchase.

Think they may be the same
I have the OS95 and its ugly, heavy, works flawless and built like a tank.

I have an inshore Fin Nor that I'm very happy with (apart from, as you mention, the fact that it's heavy for a reel in its size/line capacity class). I think I'll go ahead and order the OS45, seems perfect for heavier surf casting plus surface action on offshore trips.

Was originally bought for beach and off shore use, everything from some sharks to tuna and has preformed flawless, they may hold more line of any, that I am not sure of mine has 450 yds of 100# braid and is not full and has backing, excellent drag numbers also, if lost I would replace it.