4- the current plastics are held on by a little rubber nut that looks like it pushes on should I order the same rubber nuts as a replacement or should I order the same plastic ones that are on my FP & Flash. Factory are the 6/32 Nylon nuts.

http://www.rtbb.com.au/catalog/product_info.php?products_id=2730&osCsid=e4d05c26e0c210b086dad349709fc448