Hi
In the UK we tend to get the aft strap as far forward as possible above the prop in the gap between hull and prop. Ensure you do not get the strap on the prop as I have seen a few Vegas lifted that way and ends up with a bent shaft and expensive repair. The forward one is located at the chainplates for the forward lowers. Ensure both straps are also tied together to stop any slippage. Once you have lifted the first time,mark the Vega with stickers so you will know in the future where to lift.
Hope this helps.
Steve Birch