I can’t answer your value question.  I know only a little about these.  A series of five Factory adorned rifles in heavier chamberings. To recollection, issued serially and something over a hundred @ chambering manufactured. Seem to remember some hearsay that after disappointing “set” sales, they became available singly.

To discuss further such investment in ‘generalities’ for your consideration only. 

I’d suppose the absolute upside from collector standpoint, exactly as you infer, a complete original, unfired, group of all five chamberings as “from factory” with all ‘accoutrements’. Oh my! 🙂 

The downside, absolute safe queens… Space, investment, gazing. I suspect that of those sold as sets, most sold, amounting to speculative buyers.  Seems to me, appealing to a very limited collector audience.  The “limited edition” folks, well healed and prepared to ‘sit on’ their collective investment.  I doubt there is anything to be fairly termed a “market value”, too limited transaction numbers and subject to too many vicissitudes of such limited group interest.  The ‘value’, literally predicated upon ‘right person, right time’.  The trick, I’d suppose, to determine the ‘right time’ and best ‘sale venue’.  Same as about any investment!   

With luck, perhaps t get a ‘spot-on’ answer here.  Most realistically, if a prospective seller,  I’d be scouring the Internet and particularly the big Internet gun sale venues.  

Adding my own prejudiced personal proclivities & prejudices…  Acquiring such “under glass” guns for me, about such fun as marrying a beautiful woman for “platonic purposes” only!  

Best & Good luck!

John

iskra said
The downside, absolute safe queens… Space, investment, gazing.

 Like all the other commemoratives, which is why I never had the slightest interest in any of them; might as well collect Franklin Mint, which, at least, nobody would break into your house to steal.