The corvette June, and anachronistic design

I tried my hand at doing an 1860's corvette as an anachronistic design. I chose the Juno, as it had fewer guns. I had to extend my system to handle the 64pdr MLR. The anachronistic Juno can make 18 knots and has a twin 5.5in turret forward and 4-4in guns on the sides, in mounts with shields. The range is 4,700nm at 12 knots. This is the Springsharp report:

Juno, Great Britain Corvette laid down 1906

Displacement:
 1,641 t light; 1,710 t standard; 2,083 t normal; 2,381 t full load

Dimensions: Length overall / water x beam x draught
 203.94 ft / 200.00 ft x 40.00 ft x 16.50 ft (normal load)
 62.16 m / 60.96 m x 12.19 m  x 5.03 m

Armament:
      2 - 5.50" / 140 mm guns (1x2 guns), 83.19lbs / 37.73kg shells, 1906 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1906 Model
   Breech loading guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 294 lbs / 134 kg
 Shells per gun, main battery: 150

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Ends: Unarmoured

   - Torpedo Bulkhead:
  0.50" / 13 mm 120.00 ft / 36.58 m 16.50 ft / 5.03 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm
 2nd: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 5,608 ihp / 4,184 Kw = 18.00 kts
 Range 4,700nm at 12.00 kts
 Bunker at max displacement = 671 tons (100% coal)

Complement:
 153 - 200

Cost:
 £0.200 million / $0.799 million

Distribution of weights at normal displacement:
 Armament: 37 tons, 1.8 %
 Armour: 215 tons, 10.3 %
    - Belts: 0 tons, 0.0 %
    - Torpedo bulkhead: 37 tons, 1.8 %
    - Armament: 60 tons, 2.9 %
    - Armour Deck: 104 tons, 5.0 %
    - Conning Tower: 14 tons, 0.7 %
 Machinery: 795 tons, 38.2 %
 Hull, fittings & equipment: 595 tons, 28.6 %
 Fuel, ammunition & stores: 442 tons, 21.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   1,244 lbs / 564 Kg = 15.0 x 5.5 " / 140 mm shells or 0.5 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 1.7 ft / 0.5 m
 Roll period: 12.7 seconds
 Steadiness - As gun platform (Average = 50 %): 87 %
   - Recoil effect (Restricted arc if above 1.00): 0.36
 Seaboat quality  (Average = 1.00): 1.25

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.552
 Length to Beam Ratio: 5.00 : 1
 'Natural speed' for length: 14.14 kts
 Power going to wave formation at top speed: 65 %
 Trim (Max stability = 0, Max steadiness = 100): 70
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  18.00 ft / 5.49 m
    - Forecastle (20 %): 14.00 ft / 4.27 m
    - Mid (50 %):  14.00 ft / 4.27 m
    - Quarterdeck (15 %): 14.00 ft / 4.27 m
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 14.32 ft / 4.36 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 274.7 %
  - Above water (accommodation/working, high = better): 97.5 %
 Waterplane Area: 5,595 Square feet or 520 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 61 lbs/sq ft or 299 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.83
  - Longitudinal: 5.12
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is extremely poor
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily