Custom water pump pulley?

I am finishing the Rover V8 TR4A project and ran into a problem with the water pump pulley. The car is a combination of stock parts from various years as I had to select things around the Vintage Air AC system that made it challenging. The car is using the following:

Rover 3.9 engine block and heads

Buick V6 front timing cover and water pump (aims the water pump down to clear the AC)

Rover P5 front pulley/balancer (smaller than the huge Rover pulley)

1 wire alternator

The problem is that since the engine balancer pulley is static, I need to adjust the alternator bracket and/water pump pulley locations to ensure the belt is not at an angle. The alternator and front pulley can be aligned but the water pump pulley is slightly out further than the other two belts and this misalignment is a problem. I need a pulley the same size as the one in the pictures below, but it needs to be about 1/2 deeper (as I can shim it back out to make it perfect).

So a pulley that is  deeper would bring the belts into alignment (with some shims) but it only needs to be about 1/2 inch deeper. In looking at various catalogs, there are deep pulleys for a Buick 400 but are way too deep and  don't clear my AC belt, so I just need a single pulley for this application. Current pulley is here.

Any ideas on how to get someone to make me a custom pulley or is there another option that I am not considering?

I have a feeling a single groove pulley for a small block chevy with short water pump may be your savior here. 

If not - know anyone with a lathe?

It would be a tedious process, but there are basically three bolt patterns for v-belt water pumps.  You might find an application that will bolt right on.  Even if you don't, just find the right offset and drill your own pattern.

question is... how do you find the right offset?

I would start first with Chevy/BOP.  Not because I think it's the best bet, but you can probably post on any one of a dozen forums with "how deep is a pontiac water pump pulley" and get an answer in 4 minutes.

Another idea... take a different pulley and cut off 1/2" of the face.  Cut off the face of your current pulley and weld on the new hat to add backspacing.

Oh, also... racing catalogs.  Afco used to be my go-to but not sure they do pulleys anymore.  Someone out there sells pulleys by depth, groove, and bolt pattern for exactly this reason - fabricators and swap folks.

8 pages of water pump pulleys here

As always, you guys rock! Keith, my first thought was to get someone to turn one on a lathe, but if there is something close off the shelf, that will be my first step. Guess I'll start looking at specs and see what is out there.

How much does it need to move?

You may be able to press the water pump shaft in a little deeper.