Germany, 1853

Assuming the Leipzig commercial Loth = 14.60 Grams (0.4694 Troy Ounce), which makes the most sense here, "should be worth 4.25 Thlr." :

At retail rate, the Mark was Thlr. 96. ; 1 Kilogram (96.606 3-Rouble Coins) was Thlr. 410.57 (Fr 1,505.)  The intrinsic Scrap Bid rate for the 3-Rouble Coin was stated at Thlr. 1.50 - 2. Intrinsic value at the retail Platinum rate would be 4.10 Thlr per coin, but the Scrap Bid rate less than half the Seller's Retail Price.


1853: 1 Troy Oz. Ag (Coined, ~9 Roubles, Ag) = Thlr. 9.69 
1853: 1 Troy Oz. Platinum (Coin, Numismatic Rate?) = Thl. 6.21 (Fr. 22.77) 

1853: 1 Troy Oz. Platinum (Wire, Retail) = Preuss. Thlr 12.773 ; Fl 21.921

1853: 1 Troy Oz. Platinum (Bid: Scrap Low) = Preuss. Thlr 4.508 ; Fl 7.89
1853: 1 Troy Oz. Platinum (Bid: Scrap Avg.) = Preuss. Thlr 5.26 ; Fl 9.20
1853: 1 Troy Oz. Platinum (Bid: Scrap High) = Preuss. Thlr 6.01 ; Fl 10.515

The semi-manufactured Platinum sold retail for nearly an identical rate in Paris (1853: Fr. 46.82) and perhaps abit less in London (1852 £ 1.56) if £ 1.92/ozt. in Germany.

1853: 

The metal value of the Platinum Ducat (3-Rouble) is hard to determine because the price of Platinum is very different, dependent on the processing it gets. In Leipzig, Platinum Foil (1/2 Linie thick = 1.09 mm) costs about Thlr 6. per Loth (14.611 Gr.), so a Ducat should be worth about Thlr. 4.25.   Notwithstanding its value, you get no more than Thlr. 1.5 - 2. for it. - In Russia, the Platinum Ducat may not be introduced again.

Citation: Neueste Münzkunde: Abbildung u. Beschreibung der jetzt coursirenden Gold-... Ludwig Fort (1853)
 

The Platinum Ducat (3 руб Pt) = Preuss. Thlr 1.75 ; Fl 3.063
The Platinum Double-Ducat (6 руб Pt) = Preuss. Thlr 3.50 ; Fl 6.125

c.1852: 1 Troy Oz. Platinum (Coined: Scrap Avg.?) = Preuss. Thlr 5.257 ; Fl 9.20







1853: 1 Troy Ounce Platinum (Semi-Mfg) = Thlr. 12.76 -14.88 
.... (USD$ 9.23 -10.76)

Citation: Zeitschrift, Vol. 6; Österreichischer Ingenieur- und Architekten-Verein, Österreichischer Automobiltechnischer Verein (March, 1854) p.126

c.1853: Platina Ratio, to Silver & Gold.


Leipzig Weight: 1 Commercial Loth (Leipzig) = 14.5875 g. or 14.592 g. (English Avd. Grain)
(The Apothecary Loth = 0.4867 English Troy Ounce.)  

c.1847 


Elsewhere suggested: the Leipzig Pfund of 32 Loth (at 467.5501 Grams or 15.0320831 Ozt.) so the commercial Loth = 14.61094063 Grams; 0.4697 English Troy Ounce.

Or, here: the commercial Loth = 14.6133 g.