It took a couple of weeks for the RTL8029 to arrive, after which time I had a host of other problems running bvision and bppc.
Plus, in trying to repair a B1240 which I'd bought as non-working I managed to fry my a1200 motherboard, although I didn't realise this at the time - a couple of weeks later the graphics started to corrupt, then got yellow screen of bad chipram on startup, then I couldn't even boot up workbench from the hard drive.
I never got around to trying, and have totally disassembled the 1200/ppc setup at the moment. Sorry.