If you buy a copy of "Magnum: The S & W .357 Magnum Phenomenon" by Mullins (Collector Grade Publications) you will find a photo of RM #1 inside. That is as close as anyone may get to seeing it
.
I would also carefully use your current RM, but there is no harm in posting a Wanted to Buy ad here for a shooter grade one. You may find they work exactly the same.
There was a recent post here by someone who had inherited (?) what appeared to be a complete RM package with certificate, don't recall if it was a LE gun but I think not. (Edit to add - this person may have been you
).