FWIW, I looked up an old spreadsheet I have (from about the year 2000), where AR822218 is listed as a 1963 LHD Sprint belonging to "Dial Aircraft" in the UK (no address info or believable date of last contact), and the color given as Visone (Maroon).
AR822220 is listed as a Rudd RHD conversion, and so are several other chassis numbers in about the same number range (+/- 200 chassis numbers). So, I'd say there's a fairly good chance that (a) Rudd probably converted a batch of cars, and (b) AR822218 may be a Rudd conversion.
[SIZE="1"]'63 2600 Touring Spider (AR 191437, the car that started the 2000/2600 International Register, reassembly in progress)
ex-'65 2600 SZ (AR 856043, the car in my avatar, sold as resto project to Austria)
Maintainer of a private 2600 SZ register (not the one in the Netherlands).[/SIZE]