Definitely a 160cc. All the powertorque engines were. Keep an eye out at your local tip for one, they're generally fairly cheap and you can harvest the blade carrier and the height adjustment segment for it. Alternately your local mower shop should have a good 2nd hand blade carrier for about $10 and you can repair the height adjustment section with some welding and a die grinder. Joe Carroll may also be able to help with the height adjustment section. He's one of the gurus on this site and i believe is based in Leeton so you could either go out and pick one up or he could possibly post one out to you.
Good luck with the resto and keep us posted on your progress and any questions you may have.
