I’m looking to buy 1977-1979 175 cases. My engine threw a rod and has unrepairable damage.
please let me know if you can help.

Thanks 
 

I have no luck linking ebay or doing a search using the number. Hope its just me & you have more luck.
Gotta hope the bearing rings are still tight in the case. RH looks ok but not sure on the left one but could be ok & just needs a clean.
Found another set i can't now find a second time but i could just see punch marks around the left bearing ring so be careful if you go looking.
That one the pic was straight down in the top with both cases together but could zoom in & see punch marks.
eBay item number:225714036690
tabspartssYamaha 1979 Yamaha IT 175 Left/Right Engine/motor Crankcases Center Cases

I give up. I can't find it in his listings but still shows as live refreshing the page so i don't know.
But looking down in his description i see he says one bearing race loose, so not good.

Yamaha 1979 Yamaha IT 175 Left/Right Engine/motor Crankcases Center Cases | eBay

here is a craigslist link if useful.  also, facebook has a bunch of them at various prices, low as $300 (believe in OR)

craigslist IT 175