Complex sentence: Several companies and individuals immediately approached Trampier to commission new pieces of art, re-publish some of his most iconic pieces, or have Trampier appear as a guest of honor at conventions; however, Trampier refused and indicated he wished to be left alone.
Split into simpler sentences: Several companies and individuals immediately approached Trampier to commission new pieces of art, re-publish some of his most iconic pieces or at have Trampier appear as a guest of honor at conventions. However Trampier refused and indicated he wished to be left alone.