The 3.8mm. 5.2mm, 7.5mm and the 21mm eyepieces are sold; only the 10.5mm is still avaiable.
I have 5 Orion Lanthanums for sale; these were purchased new last calendar year and have seen moderate use. The sizes are: 21mm, 10.5mm, 7.5mm, 5.2mm, and 3.8mm. These are all in excellent condition and come with the original boxes. Unfortunately, the 21mm is missing its top cap, but it is in the same condition as the remainder.
$75.00 each shipped and insured in the lower 48.
Thanks for looking.