Have confidence in yourself. Your experience looks good, and people have gone onto 737s with less. Approach with an open mind and learn new ways. If it is of any interest, I did my twin training on Beechcraft Barons. I then converted to VC10 with some 300 hours. I found the PA28>Baron conversion more traumatic than Baron>VC10, though many of my colleagues disagreed. The 737 is a lovely little fluff jet- you will have no trouble hacking it.