I am a huge fan of the vintage Mission brand. Mission made some very well engineered products during the 80's. The Argonaut was the TOTL speaker, followed by the Freedom 770, Renaissance 737 and, if I'm not mistaken, the 70. The Mission lineup in the 80's does not compare with their current products.
These were expensive speakers in their day, Doug Brady & son, a high-end audio dealer in England, used to partner the Mission Freedoms with the Krell KSA-50, Audio Research SP-8 and the Linn Sondek LP12.
I have a pair of Freedoms and I used to own a pair of Renaissances. I just love them. They were quite advanced in their time, for example, mine featured polypropilene woofer cones and rubber surrounds. I have the older version, which I think looks best, IMHO. In the late 80's or early 90's, Mission released a "mkII" version of the Argonaut and the Freedom. You can tell which is which, as the newer version has a rectangular tweeter. The model name is written in a different font in Italic.
However, older Mission speakers are not taken very seriously today, and you can buy them for cheap. The speaker drivers technology has improved so much, that, by today's standards, they are considered old speakers. Despite their size, the cabinets are very light. I believe my 737s weighed less than 20 pounds each, which is nothing for a large, standmount speaker. If you're a tweaker, there's a lot of room for improvement. You could improve the internal bracing of the cabinets, change the internal wiring and do a recapping job in the crossovers.
The Mission speakers are very easy to drive, they have the very typical "British" sound. They are polite speakers, very musical and they have a very natural balance. Do not expect full loads of bass but, for the most part, they sound very nice. I believe they match very well with most of the vintage receivers and amplifiers that we love to discuss about here at AK.
Good luck and if you liked what I wrote, I hope you can buy them. :yes: