Replacing aquarium cover

[ecto04]

The cover to my 46" bowfront aquarium has cracked and I need to replace it. However, I don't know whether or not this type of cover is "standard" in size and shape. The aquarium is old enough that I wouldn't have any idea of what brand it is. Can anyone tell me if they are standard and/or suggest the best place to find a replacement?
Thanks in advance!
Mary Beth

 

[BushFishRox]

if it is the the glass lid I am sure they are std. but I am sure you can also get the broken piece replace at any glass place if you give them the diamentions.

 

[ecto04]

Thank you!