Mast base casting without step link hole?

Hey all, I recently picked up a parts boat (turned out to be in better shape than my not-parts boat!) and as I was going over it noticed that the mast base casting does not have the hole drilled for a step link, and the flange where it would be is tapered to a much sharper point than on my 1981. By the sail pattern (pale yellow and white sunfishy stripes) I'm gonna say it's 1970-72. It also came with a battened jib (yay! Aussie rig comin' right up!) which I had never seen before on a H14.
Does anyone know exactly when the mast base casting started being produced WITH the hole? I plan to drill one; this is simply curiosity.
Thanks!

The original mast step on a Hobie 14 had no provision for a link (which didn't appear on 16s until the late 1970s and was later adapted to the 14).

The original technique for stepping the 14's mast was to rotate it vertical with the base stuck into the sand just in front of the front crossbar, then lift the mast vertically and drop it into the base while your buddy hooked up the forestay.

Needless to say, this proved to be a difficult technique for some people to master, so they changed the mast base to have a hook, which engaged a horizontal rivet located in the mast step where the link hole is now. Unfortunately, the hook tended to break and/or become disengaged right when the mast was at it's greatest compression, resulting in a lot of dropped masts. Thus the invention of the captive mast step link.

Thank you, that's interesting info. I've seen pictures of people picking up their masts vertical and simply plopping them into the step and marvelled at what strength it must take to do that, especially on a breezy day!
My crossbar casting does not have the horizontal rivet anymore; however, the hole is there, and it appears identical to the casting on my 81. I'll simply regrind the mast base hook and drill using the newer equipment as a template.