Looks like the it's either the MMC comfort kit fitted to the steering arms without the top brackets or it's a one off/home made similar arrangement. If it's the latter and turns out to cause any problem then it could be swapped for the full MMC arrangement. It doesn't have the Empire kit wishbones.
The air filter looks to be standard, just with the Sopwith Pup "In the event of the propeller or engine being removed the gun MUST be retimed" brass plaque.
Not having the Centa wouldn't be a showstopper but you might want to budget for getting it done if it hasn't already been converted.
Good luck!
