20' Sceptre I/O, blower/ventilation question

[MATDKAT]

Hi Gang,
New member, you guys have a great site here! Lotsa good info. Recently bought a 1977 20' Sceptre I/O, newer Mercruiser 3.0L. Here's my first question:
Found that the bilge blower motor is shot, will have to replace. Looks like it is a flange mount blower, mounted up top on the stern. While looking at, see that there is a wood trim piece about 1/4" thick that covers 4 ventilation openings all close to each other. The port side back opening has the blower mounted onto it and it's hose runs down deep into the bilge. The other 3 openings also have ventilation hoses attached, but the hoses just seem to drop at various lengths down into the bilge also. This seem to be correct to you guys? There are no vent cowlings up on the bow at all. Anyone have a 20' Sceptre I/O with similar setup? Would appreciate any advice for proper configuration.
Thanks,
Dan