Fresnel Lens + Arri Question

[iamlance]

Hey, I recently purchased a used Arri 300w light for very cheap (like $124 cheap), but only because there were a couple problems with it. Most are easy fixes or only affect the aesthetics.
The biggest issue is the fresnel lens is cracked down the middle. The seller did say it didn't change the light much, but I am skeptical.

I won't have another Arri to compare it to, so what should I be looking out for in terms of quality loss? I am figuring out whether I need to replace it or not.

Also, the Arri light is the old version, not the plus version. What exactly is the difference between the two?
Is it just the internals that are different, or was the whole structure changed, so screws/lenses are not compatible between the two?
I am having trouble finding the old style lens and am wondering if the newer lens will work. http://www.filmandvideolighting.com/ar300plfrlen.html

EDIT:
http://www.lightsonretail.com/Merch...ode=ARRI-L4_79224_E&Category_Code=Arri-Lenses
http://www.lightsonretail.com/Merch...ode=ARRI-L4_79207_E&Category_Code=Arri-Lenses

The prices between these two lenses are very different, and as the description mentions a different mounting method, can I make it work?

 

[dwiener]

If it is a clean crack just splitting the lens I wouldn't worry about it. If there are chunks of glass missing along the crack than I would replace it. I don't know if there is any size difference between the old and new models. You might try Barbizon in Orlando.

 

[iamlance]

Here is a picture of the crack:


So you don't think it will 1. fall out while shooting, or 2. affect the appearance of the spread of light?

I've ordered from that Barbizon before, so might give them a call if this does need to be replaced. Hopefully they'll have a lens a little cheaper.

 

[dwiener]

It will probably be ok light wise , you can press on the lens and get an idea on how secure it is. Any hard drop of the light and all bets are off.