There were more late season international signings by the Astros: ( Jayne @ What the heck bobby does it again.)
2/28/18: RHP Jherson Pereira signed out of Venezuela; he was 21 in January
In addition, I somehow missed a few international signings from the end of last season. It's a mixed bag as far as the information I could find, but here you go!
9/22/17: LHP Julio Robaina, originally from Cuba, signed for $220,000; he will be 17 later this month and is reported to throw in the low 90's with a developing curve
8/30/17: SS Hector Leon signed out of Venezuela; he turned 17 in February
8/24/17: RHP Franny Cobos, a converted pitcher out of Cuba, signed for $125,000; he turned 17 in February
8/23/17: RHP Jeremy Molero signed out of Venezuela; he was 18 in November
8/21/17: IF Rolando Espinosa, originally from Cuba, signed for $175,000; he turned 17 in January
8/18/17: LHP Daniel Bello signed out of the Dominican Republic; he was 21 in January
8/14/17: C Jonarkys Lopez signed out of Venezuela; he will be 17 on 8/13
8/9/17: SS Jose Mendoza signed out of Venezuela; he will be 17 on June 19th (click on link for a short, artsy video of Mendoza)
7/20/17: SS Sebastian Grullon signed out of the Dominican Republic for $150,000; he will not be 17 until July 19th