I've got a ball raced Enya 35 with the square intake and (unusually for me ) it's also got the RC carb. The needle set up is similar to some of the earlier OS carbs where the fuel nipple is part of the needle valve body but the OS uses a much smaller diameter thread to go into the carb body. If you can't get the Enya needle and have access to a few tools then an adaptor could be made so the OS needle would fit (external thread to suit the Enya carb and internal thread for the OS needle valve).

Assuming yours is the plain bearing version, my Enya chart shows that the RC version has .6HP with a rev range of 2500-13000. The CL version has .8HP (larger venturi throat) and a useable rev range of 8000-16000. Use a 25% all castor fuel if possible and it'll last forever

Edit to add...I had a quick look at my Enya 45 and it seems to have the same needle as the 35.