I run a UK loco repair shop, have never installed r/c in a Sabrina (never even seen one) but I have on many other Accucraft locos. Frankly, without one on my bench in front of me I would not know where to start with a Sabrina, but if I did have one here it would be the usual procedure for a loco not encountered before: Sit and think about it, hold the components in various places and wonder "Would that fit there?". And it is that process that takes time and has to be paid for. However, it is something you could do yourself rather than just copy somebody else's work.I've been told that several UK loco repair shops have installed R/C in Sabrinas, so it has been done, but no one, builders or loco owners have responded to picture requests.
It comes as no surprise to me that no commercial shop has posted pictures. If I had done an install I would probably ask the owner to keep the arrangements to themselves rather than giving away my commercial information. Taking on challenges such as this is what puts food on my table.
One piece of advice though: Accucraftt metal of all types is immensely hard. If you need to drill holes, especially in their stainless steel, a normal drill will not do it and just go blunt.