I think it's OK if you are referring to the post through various merits and they can be useful to visitors.
Like if you link to widget, you link it via "history of widget", "use of widget" to the same page.
One thing important though is not to overdo it that you repeat the keyword over and over which can get trapped into the imaginary spam threshold.
If you have a good themed site, I would even take out "widget" from the keyword from linking. And just left in check out the "detailed history", or read more about the "color".
Navigational links get ignored by Google as it indexes and fully indexes the pages on the site. (Is it repeated over and over on all pages? If so, ignore and don't show on the SERP) However, during the index infancy they DO get indexed as a part of the content which can result in nasty stuff happening. Again, the key is not to keyword stuff. But since your site appears to be established with traffic and navigational links there for a while, you shouldn't run into that.
You never ever want the navigational links (keyword enriched) to be indexed as a part of the "content" as you can get a ton of irrelevant visits. This method can get you initial traffic boost, but will hammer the site or get the site labeled with manual spam. I did that with one of my site with navigational spam and throw the domain away, as a testing project.
Bottom line: Is it useful? Will your visitor find it useful? Will they click through the links and net you more PV's and potentially conversions? If so, it's probably OK.
If you do it only because you want more pagerank or whatever trust to flow to the page? It probably won't work the way you want it to. Search engine won't give that page more weight if visitors do not flow to that page naturally. But if they do click that link often and find that page highly relevant and interact with it in some way, you will see success.
Avoid keyword stuffing aka repeat the keyword over and over again to hope for improve ranking. This means varying anchor even if it points to the same page, as you probably want to mention the same page for various purposes.It may help or it may not in the short term (1~2 month ranking / traffic), but in the long run (6 month+) it probably won't.