The first CD from Mission was the DAD 7000. It was one of the very first "audiophile" CD players along with the original Meridian MCD. Those two companies went on to make top CDPs for several generations. Meridian went a bit more high end, Missions were cheaper than Meridian but much more than mass market machines.
If the machine in question is very heavy it is probably a DAD 7000. This was apparently just a standard Philips 104 14 bit 4x OS with some additional filtering on the analog output to make the 1st generation CD technogy more listenable. A very cool 14" wide machine in that it is all metal and inspires some confidence BUT: somewhat clunky mechanism, really cheap captive RCA leads and a laser that is probably burnt out by now. I picked on up years ago and it had terminal skipping, a fate that awaited most of the machines we sold. Some people like to mod these, but I doubt it is worth the effort. Not worth a lot of money (any money?) unless you care about the "historical" aspect. The DAD 7000R had a remote.
The follow up was the PCM 7000. Better sounding, another Philips machine but with a Mission board somewhere inside. Can't remember if this was 14 or 16 bit. Very striking big, colorful display. Too bad the machine itself was all plastic and felt cheap. The drawer was awful. The PCM 4000 was just a standard Philips in the cool looking PCM 7000 box.
Next came the PCM II. By now 16 bit 4x OS for sure, TDA 1451 chipset. Still a lot of plastic, but better feel overall than the previous model. Great sound. Came out high, near $2000 Canadian as I recall but kept in production for a long time as far as CD players go so they kept dropping the price. At the end I think they listed at $799 and were a great deal. We were told they upgraded to the "Crown" version of the 1451 at some point, but I never checked and given Mission's tendency towards hype, I would not vouch for this actually being the case.
Finally there was a return to the 14" size with the first 1 bit machine, the DAD 5. The whole transport came out like a plastic version of the Revox B225. Lightweight machine, we felt it was step back from the PCM II. The sound did improve with the clever little outboard DAC, the DAC 5. Side by side both units were a standard 17".
After that I think the CD players were Cyrus, not Mission so I will wrap up the history here. I welcome anyone to add on what I have missed and correct what I got wrong.
Last year I found a near mint, except for the STUPID green marker scribbles all over the inside of the drawer, PCM II with all boxes and paperwork for $90 Canadian. It is the only used Mission CDP I would recommend buying now, though a DAD/DAC 5 combo would be nice as well.
Let me know what happens with your Mission.