:lol: Sorry, I didn't make a video... but I promise it can be done without any :BangHead:
There are just very few mushroom cams around any more, since there are so many rollers available. But everyone who's run this Mini-Express has liked it.
Anyhow, on the original subject, I really think the .620 cam is too big for the OP's setup and intended use, likewise the GK mushroom. A .557 or maybe the .590 would be a better match.