40 Plus Mounting/storage frame

[Rangeley Guide Boat]

Hi all, new guy here. Love the site, I've been lurking a bit as I prepare to freshen up this '65 40 Plus. It was family owned, well cared for, but has been stored a looooong time. I think I have my original crop of questions answered by perusing the forums and John's site, I've got my 140 weight gear oil, new plug, a few cans of gumout, and I'm ready to go! My question is this: the motor came mounted on a sled-like contraption, which appears to be purpose built to hold the motor. Is this an original part, possibly the insert for the shipping crate? It doesn't appear to be a home built piece....It's not too handy, but it's there............Anyone seen one of these?