The lack of easily available good quality 1/2A and .061 size engines is indeed a worry, particularly the unavailability of the Norvels which in my opinion are unmatched as a 1/2A size sports engine.

For C/L flying, I am coming to the conclusion that the solution is to turn away from the US definition of 1/2A and use the many superb, readily available .09/.10 size engines. In particular the Enya .09-IV is wonderful, and of course the PAW .09 is no slouch either, plus older Enya 09-IIIs, OS 10 FSRs, 10 FPs, etc. are easily obtained on eBay for very little price. Also, Carlson still offers the MK17. If diesel operation is desired, the PAW is great, and of course Davis offers a conversion for the 10FP.

Regarding CS, I'm inclined to agree. My CS olly is a great runner after significant remedial work by David Owen (including fitting a couple of Rothwell parts), but frankly for the bother of the thing I'd have been better off just buying a PAW or some more OS 15s on eBay, or even a Marz.