Hi Blumbly
The bases are very different on both sides here some better pictures that might show it better
4 Star
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/01/full-7423-14424-base_4_star_1a.jpg)
4 Stroke
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/01/full-7423-14425-base_4_stroke_1a.jpg)
The other side
4 Star
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/01/full-7423-14426-base_4_star_1b.jpg)
4 Stroke
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/01/full-7423-14427-base_4_stroke_1b.jpg)
Also the base is different when the engine fits and is listed as 2 parts in the Victa books you can see the difference as below, the engine mounts
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2014/01/full-7423-14428-img_0001.jpg)
AS you would know the 4 Star was made from 1960-61 the 4 Stroke 1961-62
I wounder there is a over lap of models or was the base shape changed while is was still a 4 Star which would explane that your two bases are the same
Ian