My experience with Steve Mogg to put it bluntly has been dire, I ordered a DSLR focal reducer in December last year (2009) and it turned up early February this year. Unfortunately it was damaged and Steve agreed to send a replacement, at this moment in time (May 2010) I have yet to receive the replacement, for the past 3 months I have sent weekly emails to both his addresses and have not had 1 single reply.
His service is a disgrace and I will never use him again or recommend him
Since my purchase I learned at a local star party that a couple of guys who were present had had the same problem but had given up on refunds or replacements.
Use Steve Mogg at your peril.