Hello Eddie,
Billing Boats used to have most of their kit instructions available for download from their website. However, the last couple of years, service of any kind from them has, from what I hear, been a bit hit and miss, and last year their old website went down for some time.
They now have a new website up and running (**LINK**) but, alack and alas!, no longer with those downloadable files.
What seems to have happened is in fact that what up until last year was a family business, run first by the original Mr Billing, and then by his heirs, was sold in 2015 to another (Danish) company, Vestergaard A/S, that seems to be focused mainly on RTR models and toys.
Given the, from what I've heard, somewhat erratic running of the company in the last few years before it was sold on, one can always hope that this will mean a more professional approach to customer service, although there is of course always the risk that it'll be more of a corporate approach (which in my book is not necessarily a compliment).
Anway, you could always, on the off chance, give them the benefit of the doubt and write to either Biling Boats or their local distributor where you are (Ripmax in the UK, it seems) and ask if they could let you have, or sell you, a copy of those instructions. Worst case, they won't even bother to answer; less bad case, they'll politely say "sorry, no can do"; best case, they'll send it to you. In either case you'll be no worse off than you are now, unless you count any minor frustration that might arise in the process, and in the latter you'll have what you were looking for!
Good luck,
Mattias