Hi Dean,
You should be able to get most parts for the 348 from one of these suppliers
southwestmontesa.com (Jared Bates - US), rmmontesa.com (John Haberbosch - US), inmotiontrials.com (UK),
http://www.users.bigpond.com/bultaco.oz/ (Bultaco Parts Australia),
http://www.newellmotorcycles.com.au/bultaco.htm (Don Newell - Qld) all these suppliers are excellent and highly recommended.
also EBAY
Most badges you will find are a flexible reproductions not the hard NOS items but still very good quality.
Greg
Sorry I corrected the WEB address for Rocky Mountain Montesa (rmmontesa.com)