Yes, please do - it's a modest gesture compared to what you and others are doing for those two lads.
Seeing that you're starting here in Liverpool, I'd love to join you for the ride. But it happens to be the day of my 60th birthday, and I can think of one dearly beloved person who would be less than pleased if I finished the day 120 miles away in Nuneaton
Anyway, the butterfly bars... I got them a couple of years ago when I was also building a touring bike - mine is based on a 1980s Raleigh Royal touring frame I got for £40. I know a lot of cycle tourists love them and it seemed like the ideal time to try them. And they're actually very nice - I can see why people like them so much as they offer some very comfortable hand positions.
But I think that, after my decades in the saddle, my brain is so tied to the randonneur pattern drop bar that I just can't manage without my drops.
So, the butterfly is all yours if you want to try it - and if you find you don't like it and don't want to keep it, just pass it forward to someone else.