Ok so I have one of these fitted already, in fact I've always put them on each boat I've owned. Today I put a new shaft in the boat and I didn't have the little plastic dooverlacky that holds the lip seals aft inside the gland.

My question is... Is it super easy to reverse the lip seals or would this be an uncommon out come if the propshaft slid through easily?

Can anyone give me an insight into how likely it is that the lips could face the wrong way?

when I had my h28 I removed the Volvo seal and didn't have the plastic slide when I reinstalled it I used plenty of grease but when I put the engine in gear I didn't stop dripping
I ended up cutting some thin plastic from a bottle and pushed the lip back by sliding the plastic between the shaft and the seal while still in place in the water , I used cable ties to hold the plastic to the shape of the shaft as I pushed it in
not my idea but it worked fine no drips

You can use a feeler gauge to do the job, or cut a piece of thin plastic into a strip. Its also a good way of cleaning dirt out of the seal in many applications eg; Dirtbike fork seals

Did you burp it ?