My car is a 1996 N reg, hence it getting another Nikasil Block. My Dad has an M52 engined 528i which is a 1997 P reg, that got the later Alusil short engine when BMW exchanged it - as did my previous 1997 e38 728i -, I'm surprised that a 1997 R reg example has not got the later block in it, makes you wonder if BMW did the recall on that car at all and if not, why not? - Points to a possibly patchy dealer history perhaps?
The niksail problem was never considered a recall, BMW only replaced engines which had problems caused by the nikasil lined block. Thus if your car didn't suffer any problems there was no reason to change the engine. I also have a nikasil block in my 328i sport and it runs like a peach
Sampo, do ring BMW up with the cars vin/reg number and see if there any outstanding recalls such as steering spindle. The steering spindle recall was issued over 10 years ago and they are still replacing them now.
Rob