Having three Marlin 39's might be considered over-indulgent. I enjoy(ed) each of them but found the Moutie to be so perfect the others stayed in the safe. So, when something else came along (Marlin 1894CB) I was willing to trade one.
SPF is the 39TDS. Good accurate little carbine. The niche it filled in my collection was for an inside the pack carbine. It was a little heavy for the role, and took up a lot more space than a Single Six. If a rifle/carbine is needed there is very little penalty incurred in weight or size by utilizing the Mountie. Not really considering myself a collector, I was willing to part with it when another deal intrigued me.