wondering what the re-sell value is on this stuff.
A bit of a smartass, but honest, reply: whatever the market will bear at the point in time you're selling and the duration for which you are willing to list it (obviously w/o having cash in hand during this duration).
Ask for a price a bit higher than you want - if someone jumps on it, great. If not, either you're willing to wait it out until someone comes close to matching your asking price, or if you're in a hurry lower the price.
My general rule of thumb if the gear is in very good condition: 85% of new. Obviously, pricing is condition and sometimes age dependent. I would put your wmod-UA5 and Oade battery pack in the 85% category. If it was me, in this case, I probably wouldn't take less - but I'm generally never in a huge hurry to unload gear (took me a looooooong time to sell my AK30 caps!). Homemade stuff is a tougher call, maybe just the cost in parts. FWIW...