Forgot to put when using the Wayback machine you need to search for rf-demon.co.uk/ and rf-demon.co.uk/index.htm, Hands changed their web site around 2000 and you need to look at both, a quick look shows there must have been around 100 different kits.
There is a bit of RMX10A info there, a schematic but no instructions or component values the RMX10 might use similar filter components but it is at least a starting point.
https://web.archive.org/web/19990218...o.uk/rmx10.htm
Andrew G7SEG