Those eyepieces look like standard, not wide angle eyepieces.
I would expect them to be the same as those on similar looking 10x40 and 12x50 binoculars.
However, only a repairer would probably know.
An 8x30 with the same eyepieces would probably be the cheapest option.
The Swift 15x60 is no joke. Should be nice.
I have not come across this model. Maybe not imported to U.K.?
I used a specially made Soviet 20x60 for years.
It is possible to see Jupiter's two equatorial bands with 20x or 22x, possibly 18x, but somebody with very fine might see them...