centrepin or fly reel?

I have one reel that measures about 160 mm across the diameter of the entire reel, and about 140 diameter for the actual spool. the spool is about 25 mm wide and there is no lineguard. That is without doubt a centrepin reel - at least in my mind. Some old salmon reels are around this size, I believe, but there is no room for a fly line...

I also have an old Allcock's reel, with a spool about 40 mm wide, and also 55 mm spool diameter, the overall diameter is about 90 mm. It has a lineguard. Now I am sure that's a fly reel as it has width and depth to take a fly line...

When I was a kid I had a fly reel I used as a centrepin - and so did other kids I knew.

How can anyone tell for certain whether a reel is a fly reel or a centrepin?

Post a photo if you can, Some of the guys on here have collections of pins and I am sure someone will be able to identify it.

Hi
I think unless it is relatively recent a fly reel will have a small centre no more than 20mm in diameter where as a course fishing center pin will have a large centre only slightly below the total diameter of the spool.
A recent change to fly reel design has been "large arbors" ie a bigger centre these reel being designed for playing the fish often with a drag rather than the older reels witch were just a line store and fish were played from the hand