Lead Gardens has an illustrated tutorial on making a “classic” wargames building of the sort you see in old issue of The Courier, or in one of Charles Grant’s publications.
Free Elements LITE is a starter version of a more complex RPG where, according to the author:
This system utilizes the Elements TTRPG system, which is a freeform action system. You perform actions by describing what you want to do, and picking a skill to use. Based on that skill’s rank, check your multiplier table to see how many points it has. All checks require skill rolls from both parties to determine the success rate, regardless of what the target may be, you’ll engage in a battle of skill checks with it. If you don’t have the proper skill, you must perform an untrained skill check with it. Rate of success when performing an action determines the outcome of a battle, if successful enough the DM will allow you to describe the outcome, where if you’re within 9pts of each other’s checks the DM will describe what happens instead.
Between 1968 and 1970, wargaming pioneer Charles Grant wrote a serialized wargames guide in Meccano Magazine. The serial is now available as a free download. This serial eventually became his classic Battle: Practical Wargaming.
As it turns out, Birch Seeds, when taken apart, make amazing scale model leaves for basing and other terrain projects. it reminds me of something John Hill, author of Johnny Reb and Squad Leader once said to me about wargames modeling: Nature reproduces itself in miniature.
Flick The Ship is a free print and play game where you flick a pencil tip across a paper map to gather treasure, upgrade your ship, fight opponents and more. It is quite involved and looks like fun.