Is there a better way to do this?

[M3AN ONE]

I have an external overflow on my acrylic tank. That has a crack multiple cracks in the bottom near bulkheads. I am going to cut it out and replace the 1/4 inch acrylic with 1/2 inch. My question is do I have to cut out the old piece with a jigsaw at the seam. Or can I go up slightly higher. Is there a better way?

 

[puffers4puffers]

Just glue new over old

 

[puffers4puffers]

To be clear
Glue new piece over cracked piece
On the WET side, the INSIDE of the overflow box

 

[M3AN ONE]

problem is its not flat/level previous owner epoxied holes and when i did that the bulkhead would not fit in correclty it was on a angle.

 

[M3AN ONE]

Problem is its not flat/level previous owner epoxied holes and when i did what your suggesting that the bulkhead would not fit in correctly it was on a angle.

 

[M3AN ONE]

I dont know why I didnt think about this before but the area in gray i will remove not the entire bottom the I will install the 1/2 arylic on the inside instead of taking the entire bottom off. Then instead of 2 holes i will use 3 im going to be running 3 2 inch stock man style drains due to the limitations of room I cant do dursos and I dont see the point in a higbie since what are the chances of all 3 drains clogging

 

[M3AN ONE]

Update!!! So I broke my overflow box im pretty sure this is beyond replacement. I dont know why I thought using a reciprocating saw would work. Just a couple touches and it broke off a giant piece. Does anyone know where I can get a new one made and possibly installed?