Okay, Lets see what I have in hand:
The mouth forts were the province of the 5th Heavy Artillery Regiment, which was equipped with 4 x 240/35; 13 Heavy Coastal, and 6 Light Coastal, guns. Heavy Coastal refers to guns of calibres 210/20, 210/22, 240/22, 260/22, 280/22, and 355/22. Light Coastal includes guns 150/46, 150/40, 87/24, and 57/40. Measurements are of course in milimeters.
Ammunition available for the Fifth Artillery Regiment consisted of 456 rounds 240/35, 41 being AP, 22 HE, and 59 Capped. Others were apparently a variety of solid shot and timed/delayed fuse, and shrapnel. Heavy coastal had 1223 rounds, no breakdown; Light Coastal 2635 rounds, no breakdown. Shell figures are for August 1914.
The 8th Heavy Artillery Regiment had the mobile howitzers and was assigned to a "howitzer zone"; there were also the 3rd and 4th Heavy Artillery Regiments on the inner defences (at the Narrows).
The 3rd Regiment had 3 x 355/35 (172 shells - 20 AP, 16 HE, 36 Capped), 7 x 240/35 (518 shells - 57 AP, 42 HE, 103 Capped), 6 x 210/6.4 Mortars (193 shells total), 19 Heavy Coastal (1739 total), 25 Light Coastal (3386 total).
The 4th Regiment had 2 x 355/35 (117 shells - 14 AP, 11 HE, 24 Capped), 6 x 240/35 (474 shells - 51 AP, 36 HE, 88 Capped), 8 x 210/6.4 Mortars (308 shells total), 23 Heavy Coastal (2895 total), 22 Light Coastal (4403 total).
The 8th Regiment was sent in to augment the defences, and the 3rd and 4th Regiments also received additional guns as part of this augmentation. Their ammunition figures are for 26 February 1915, as opposed to August 1914:
The 8th Regiment had 32 x 150/10.8 howitzers (7627 shells all HE), 14 120/11.6 howitzers (ammo stats not available), and 10 x 210/6.4 mortars (602 shells, 86 AP, 171 capped).
The additional guns to the 3rd regiment consisted of: 5 x 150/40 (taken from ships and added to the defences) with 462 shells, and 18 "smaller"; which means 37mm and 47mm rapid-fire guns and some 75mm ships' guns. There were 2,076 shells in total for those.
The 4th Regiment was augmented with 12 x 150/45 (147 shells), 6 x 150/26 (969 shells total), and 4 x 210/6.4 mortars (20 shells); along with 18 Smaller Guns, with 6737 shells total for them.
Fortress Command Depot Magazines also had 5616 shells in reserve in August 1914; I'm not sure about the quantity of the reserve afterward. The Germans had approximately 500 coastal defence specialists and a Vice Admiral aiding in the defensive efforts. The source states that the Turks fired off about 4,700 shells in combat operations lasting from 18 February to mid-March, the majority from the 5th Regiment and the 8th Regiment.
References: "TC Genelkurmay Baskanligi (Turkish General Staff), Birinci Dunya Harbinde Turk Harbi, Vnci Cilt, Canakkale Cephesi Harekati, Inci Kitap (Haziran 1914-1925 Nizan 1915) [The Turkish War in the First World War, 5th Edition, Gallipoli Front Operations, Vol.I, June 1914-25 April 1915] (Ankara: Genelkurmay Baskanligi Basimevi 1993), Charts 13 and 14.
14"/35 (German barrel length, British or US description would be around 33 calibres). Shell wt 1660lbs. With the latest 4 crh shells range was about 19000 yards, with older type shell around 12000 yards
Reference:N. J. M. Campbell's "Battle cruisers : the design and development of British and German battlecruisers of the First World War era".
An article by Piotr NYKIEL,mentions about these guns:
One of the most common arguments used by those historians who claim that the main attempt of the fleet to get through the Dardanelles could have been successful if renewed on the 19th March, was that the forts were extremely short of ammunition. It is of course true if we count only the shells of the new type, of which the reserve on the eve of the 18th March was only 267. This figure however relates only to the long barrel guns with a caliber of 355 mm. and 240 mm. If we count the new type of ammunition for the other heavy guns in the Narrows (including 8 pieces of 150 mm. in the Dardanos and Mesudiye batteries), the amount increases to 1.063 shells.
The range of the 355 mm. and 240 mm. guns with barrel length of 35 calibers was between 18.000 and 16.000 meters with the use on the new type ammunition, and between 11.000 and 10.800 m. with the old shells. The range of the other "short barreled" guns with a caliber between 280 mm and 150 mm varied according to the type of ammunition between 16.800 and 6.700 meters.
According to the diary of major Selahattin Adil, Chief of the Çanakkale Fortified Region Headquarters on that day, the 355 mm. gun was moved from Çimenlik to Anadolu Hamidiye fort and the rest of Çimenlik's armament had been put out of service to be used as a source of spare parts for the guns of other forts.
My guess is that, these guns were ordered by Ottoman Empire from Krupp between 1883-1885.