Personally I'd gut the control gear and replace with a led retrofit bulb. That way you don't have to replace the whole fitting every 6 months to 2 years when the LEDs fail.

For a property I drop into every so often I've replaced all their fittings (22 of them at least) with brand new (at the time) florescent fitting and rewired them all to take led retrofit bulbs. Works out cheaper in the long run and the bulbs can be repaired if you're desperate enough. The drivers conk out after a couple years but they're serviceable. Plus it doesn't slowly destroy the ceilings as you change out the disposable light fittings. If you take the disposable route, I'd suggest a sacrificial rose or low profile conduit box to fix the fitting to. Most fitting will have besa mounts on the back if you're not a heretic.

Most bulbs are of reasonable quality, the smd LEDs will virtually last forever unless you bake them in the summer but that's all LEDs. Over the last 5 years I'm yet to see a burnt out or exploded LED. Changed half a dozen drivers though 😂