As to whether the chainring will work, there's a key point that has not been checked, at least not in clear enough terms for my simple engineer's mind. The 5 big mounting holes in the new chainring must match up exactly with the 5 hex bolts that are already in the chainset. This guarantees a tight fit and a concentric fit, for smooth pedaling and good shifting only when it is desired. The Wiggle page (nicely done, IMO!) says the PCD (in American that would be BCD for Bolt Circle Diameter) is 130 mm. So it's necessary to check whether your beautiful and high-quality Stronglight 300 (did I read that right?) chainset is designed to take 130 mm PCD chainwheels. It should be a specification given in a Stronglight catalog ir in may be baked into the filter that you followed on the Wiggle site. Or you can measure the center-to-center distance on the bike, solve the equations for an isosceles triangle, and you'll have the PCD of the chainset. The information can also be found in the charts on the Sheldon Brown site, but I'm not sure the Stronglight 300 is known in the USA by that name.

Actually, this link to the Sheldon Brown table should be what you need https://sheldonbrown.com/cribsheet-bcd.html. It says your bolt spacing is 76.4 mm for 130 mm BCD. If you measure the distance between an adjacent pair of bolts (center to center or equivalent) and you get 76.4 mm, that Wiggle chainring will fit your chainset. If not, the Sheldon Brown table will show you what specification is necessary for the chainring.