It might be genuine, though it looks a bit well preserved to me, but there are some well preserved relics, so that in itself is not conclusive. The lettering style looks a bit suspect too, but that again is not conclusive, since there could simply have been an aircraft rigger who painted letters that way. Apart from the lettering though, the bits that look slightly suspect incidentally, are the nine sitting above the baseline and the fact that the outlining of the numbers has been done on both the red and the blue overlap. It was rarely felt necessary to do it on both colours, which is a bummer when you look at old monotone photographs from the period, as the serials often blend into the national colours where it has not been outlined. The outlining itself is also a bit close to the lettering too, there was often a much bigger white outline to make such efforts visible from a good distance.
Those comments should not be regarded as definite proof it is not genuine, since you can see examples of quite narrow outlining of serials over both colours, and a wide variety of lettering styles as well, with not every rigger being aware that characters with round bases are supposed to drop below the baseline. Here's a picture of Richthofen's room back home which demonstrates the variety which could be seen on such serials:
There is also the possibility of it being a fake, but not a fake with the intention to deceive, for example, it might be a film prop from the set of a WW1 movie or TV series. That could put it in a WW1 aircraft enthusiast's collection legitimately, despite it not being a genuine period piece.
The best way to check (apart from detective work on the serial number itself and the provenance of the object - tracking down SPAD serial numbers and squadron allocations is a good place to start that, ultimately you would then be looking for photographs of that squadron with which to compare your piece) is to compare it to known genuine items. You'd be looking at material weight, weave, rib stitching if there is any, paint type, colour and penetration of the material, dope residue, and whether the distance between scuffs on it tally with the division of any ribs or stringers on the aircraft type it is supposedly from, as they should line up (you can in fact do that from an accurate schematic drawing scaled up to 1:1). All that kind of thing.
Radio carbon dating is probably not really a viable option, as you tend to need a fair bit to sample, which is of course destroyed in the sampling process as it gets burned to find the carbon radioactive decay rate. Radio carbon dating will cost between 75 and around 150 quid. You can find places online that will do it as a commercial business, but you can find university research departments that can do it for less, so if you really have a burning desire (no pun intended) to know, and of course the money to spend on it, and you can find somewhere that doesn't need 20 grams of material to conduct the test, then it is of course a possible option. It can certainly be done on material, as evidenced by the fact that it was done on the Turin Shroud some years ago, unfortunately, for the church, confirming it to be a medieval fake. Note that the closer the match in terms of year, the more you are likely to pay.
Sadly, it is relatively easy to fake such things, even quite convincingly, but where most fakes fall down is on the correct material type and paint (should of course be old fashioned paint with probably a high lead content and probably on Irish linen, although silk was used on occasion), although you can even fool radio carbon dating if you start with materials of the right age and type, such as one of your grandma's old bedsheets that she got handed down to her from her Edwardian mother and some paint form an old garage. Most famously, that kind of thing is done by using the blank frontispiece pages from books of Edwardian vintage to sign fake WW1 pilot autographs on, which gives you an autograph that will fool almost anyone if the penmanship is well replicated. Such devious methods would also probably fool a radio carbon dating process, in recent times having been employed to create the notoriously faked 'Hitler Diaries', which were written on paper of the correct vintage with ink from the 1940s.
I've knocked some up replica aircraft canvas pieces in the past (not as fakes, but for a film production, so they had totally bogus serials on them). It's amazing what you can do with a few things you can find around your house, cold tea being a favourite for staining such things to make them look old, and popping things under a grill on a very low setting being another trick people use to dry stuff out and make it brittle as though the doping has gone off, although in the case of the ones I made, they had to look fairly new. Kick a fake around your garden in the rain, and unfortunately, who is to say that the mud (providing it is the right colour and with the correct chalk content) is not from the Somme Valley? Do it in France and it could even be the case that it is the right soil.
Ultimately, if you like it, then that might be enough for you to be happy with it. Welcome to the forum by the way.
Al