Complex sentence: Later, having met a Swiss girl on an Irish cycling holiday, he moved to Switzerland in 1973, continuing to operate as a stamp auctioneer and publisher since then, running his first auction there in 1976.
Split into simpler sentences: Later, having met a Swiss girl on an Irish cycling holiday, he moved to Switzerland in 1973,. He has continued to operate as a stamp auctioneer and publisher since then, running his first auction there in 1976.