I Cannot Seem To Find These Stamps Anywhere-- It's As If They Came From An Alien Planet!

Michel lists the gold foil paper version of this stamp, but not the silver. (They usually list both, if both were issued.)

The gold foil stamp is Michel 706A, 1971, €9.00

Michel 707A, 1970, €9.00

I posted the Michel catalog values only to give relative value. I will quickly add that these particular items are on the higher end of the Trucial States issues of that period. A number of the metal foil stamps do catalog relatively high, although there are also many that don't. Most mint regular sets don't catalog that high, and used sets often catalog for even less. (No used values were given for the ones I responded to here.)

I think it's safe to say that Michel catalog values are generally regarded as high, and an actual selling price would be a small percentage of that. As to what that percentage would be, perhaps some of our European members where Michel is the default catalog choice, and who go to dealers and stamp shows, can give a rough idea of what percentage they apply to determine if a dealer asking price is too high, reasonable, or cheap.

GB auction houses tend to work on around 10% of Gibbons or Yvert for most stamps - more for in-demand items, of course - so perhaps Michel can be approached in a similar fashion.

A few years ago, I placed bids on the foil stamps, from the Trucial states,
just as a "completion thing" for my collection.
I was surprised in the morning I had been outbid on all.

Further surprised looking at the bidding, there were numerous bids from differing collectors, the prices, whilst not catalogue value, were not far off it, on some issues.