Howell Miser Question

[scooby]

I'm taking a little break from the Howell V4 engine and finishing up an engine I started but never finished, the LTD Miser engine.

My question is regarding the clear displacer ring. I ordered a piece from the howell website and the inside is not round. Measuring the ID in a few different spots gives around .035 difference in diameter. Does it really matter if its not round?

Thanks