Lots of interesting informations in both Yamato's TROMs. It seems, that in-game upgrades miss some modifications. YAMATO TROM, and MUSASHI TROM.
Yamato's have in-game upgrades at 9/43, 1/44, 7/44, and 1/45
3-28 September 1942:
Final fitting-out at Kure. MUSASHI’s initial AA suite is twelve 127-mm guns (6X2), twenty-four 25-mm guns (8x3) and four 13.2-mm machine guns (2X2). Twelve additional 25-mm guns (4X3) and a Type 21 radar are installed during this period.
While in-game radar comes in 9/43 upgrade. It seems to be actually typo, because at 9/43 both ships were out of Japan. And since Musashi arrives in December 1942, it should already include radar.
1 July 1943:
Kure. Enters drydock. Type 22 Mod. 4 radars are installed on the bridge. The Type 22 provides limited fire control.
Again, BEFORE September 1943.
24 February 1944:
Departs Yokosuka for Palau with MICHISHIO, SHIRATSUYU and another destroyer. MUSASHI is loaded with one Army battalion and one Special Naval Landing Force battalion, munitions, fuel and vehicles.Enroute, the group encounters a Typhoon and most of the deck cargo of munitions is lost. During the storm, MUSASHI has to reduce speed from 18 to six knots to allow her escorts to keep up.
Have not tried this yet, but is this possible to load ships without capacity? I surely can not do this with Allied CAs/DDs, as I tried to evacuate some units from Rabaul.
10 April 1944:
Enters Kure drydock No. 4. Repairs are made to the hull. Two beam triple 6.1-inch turrets are removed, each is replaced by three triple-mount 25-mm. AA guns. Twenty-one other triple-mount 25-mm. guns and 25 single 25-mm. guns are added. MUSASHI's 150-cm searchlights Nos. 7 and 8 are removed to make room for the single mounts. The searchlights are later reinstalled for use by Sasebo's AA batteries. MUSASHI's final AA suite is one hundred-thirty 25-mm AA guns (35x3, 25x1). A Type 13 radar and a new Type 22 radar-directed fire-control sets are fitted. Depth-charge rails are also installed on the fantail.
I am not sure DC works on BBs, but I see no reason not to. No DCs in-game.
12 July 1943:
Kure. Drydocked. A Type 21, Mod 3, air and surface search radar is installed. Twelve new (4x3) 25-mm AA guns are fitted on the weather deck. YAMATO's total 25-mm. AA suite is now 36 guns. Her 155-mm. wing mount guns are provided with coaming armor and their barbettes with 28-mm of additional armor. YAMATO's fuel storage is reduced and her main and auxiliary rudder controls are improved.
I am not sure if barbettes armor is included in turrets statistics, but if it is, either armor should be greater, with this upgrade, or initial turret armor should be lower.
Again, this is BEFORE September 1943.
The most interesting is last part. There should probably be difference in manuever rating, and endurance+fuel, between this, and previous upgrades.
13 December 1943:
The American code-breakers learn YAMATO is scheduled to arrive back at Truk on 25 December ferrying men and material.
Again, transport mission.
16 January 1944:
Arrives at Kure. Later, YAMATO is docked in No. 4 drydock to repair the torpedo damage to her hull and correct deficiencies in her armor belt. A sloping plate is fitted at a 45-degree angle across the lower corner of the upper void compartment between the two longitudinal inboard bulkheads. This modification, proposed to run the full length of the citadel, is installed only in YAMATO in the area affected by torpedo damage.
Does game takes into account sloped armor, or only its thickness?
25 February 1944:
Kure. BatDiv 1's YAMATO and MUSASHI are reassigned from the First Fleet to the Second Fleet.
Drydocked. Two beam triple 6.1 inch (155-mm.) turrets are removed and replaced by six (3x2) 5-inch (127-mm.) HA AA mounts. Twenty-four (8x3) and 26 single 25mm. AA mounts are added. Shelters are also added on the upper deck for the increased AA crews. Type 13 air search and Type 22, Mod 4, surface search/gunnery control radars are installed and the main mast is altered. Two 150-mm searchlights are removed and later installed ashore at Kure.
YAMATO is fitted with Type 2 infrared (IR) Identification Friend-or-Foe (IFF)/signaling devices mounted midway up on each side of the bridge. The system may have been based on the German Seehund IR device. It is built around a telescopic sensor that receives light-waves in the IR range and registers a readout in the radio shack. The system also includes a pair of 20-mm. binoculars coaxially mounted with the transmitting IR lamp on the bridge so that another ship can use the IR detector for elementary signaling or as a formation light for station keeping.
About this time, YAMATO is also fitted with multiple E27 radar detectors copied from the German FuMB 1 Metox R.600.
I am not sure what does every radar type in Allied inventory do (larger ships have 3 types of them).
Yamato takes upgrade in late February, and Musashi in early April, so this upgrade can be safely changed to February.
29 June-8 July 1944:
Departs Hashirajima for Kure with MUSASHI. Fifteen new (five triple-mount) 25mm. AA guns are installed. The entire hinoki deck is also replaced. YAMATO loads the 106th Infantry Regiment of the IJA's 49th Division and materials aboard.
25 November 1944:
Kure. Drydocked. Begins battle damage repairs and refit. Twenty-four older 25-mm AA single mounts are removed. Twenty-seven 25-mm AA guns (9 triple mounts) are fitted in their place. YAMATO's final AA complement is 152 25-mm AA guns (50 triple mounts, 2 single mounts).
Last in-game upgrade is scheduled at 1/45, and takes 18 days, which will put Yamato still in refit, when it already left at 15 January (and ended refit at 1st-3rd).