Help me orient the model

Hi Guys. I want to print a seal. Model is too big so I split it in half. First I tried with elastic but it was a total disaster. Then, with flex 80A I was almost successful but the model seems to be oscillating as the platform moves up or down. In consequence the layers are not perfectly aligned. Additionally, the model broke at one spot.

I am attaching the PreForm file. Can anyone help me to orient it for printing (ideally in elastic but flex 80A will be also OK)?
seal v3.form (916.6 KB)

Tilt it so it’s laying a little on its side, not completely vertical. You may benefit from an increase in the support density, too.