Windows are oversize vinyl part of an Alouette kit house from Canada

These appear to be either Series 160 1/2" thick Coil Balances, or Series 165 3/8" thick Coil Balances. Measure the thickness of your old springs to see which Series you need. If you're uncertain of the spring weights needed, give us the exact weight of the window sash and we'll work it out for you. 

Hey Bill. I'm not entirely clear from the photo, as it can be misleading reading rulers from pictures. But if you're confident the springs are 1/2" thick, then the Series 160 is indeed correct.

I would confirm the exact sash weight to be safe, as you don't want to be off on that. A bathroom scale reading would suffice. If the sash is indeed 25 lbs, then you could use a S160-9 9 lb spring and S160-3 3.5 lb spring on both sides of the sash. This would give you 12.5 lbs of support on both sides, for a total of 25 lbs of support overall. For covers, you could use the 15-150D. 

I don't know what pivot shoe you had originally; if it's undamaged you could reuse it. Otherwise show me and I should be able to narrow that down for you. Finally, see the video below for removal and replacement details. 

Either of these options would work for you, but since using one S160-10 and S160-4 on each side would add up to exactly 29 pounds, that would be your best option.