Just a few more details:
Masbate: grounded on reef Higunum Island, NE coast Samar 15 Dec 1904
Busuanga: merchant ZAMBALES (La Naviera Filipina, Cebu). Re-engined with two 4-cylinder diesels, 480bhp in early 1930s.
Tablas: renamed Masbate, then merchant CAPIZ (Teodoro R. Yangco, Manila). Rebuilt 1924.
Mindanao: merchant MINDANAO (La Naviera Filipina, Cebu)
Samar: merchant SAMAR (Manila Railroad Co., Manila)
Romblon: I have as merchant SAN JACINTO (Cesar Barrios Shipping Co., Iloilo). Rebuilt at Iloilo 1925.
Marinduque: merchant MARINDUQUE (Santiago Carrion, Manila) Recosntructed at Manila 1933.
Romblon served with the Coast & Geodetic Survey in the Philippines from 1905-1921 and Marinduque 1905-1932. Good photo of Marinduque here:
Original engines in the Shanghai built vessels was a 2-cylinder compound (18" 36" x 24")with one single ended boiler.