I just wanted to share an option that I discovered when trying to find a lamp that worked.  For top and bottom mostly, when building a custom lamp, look at certain bird feeders.  They do have some good potential.

Mine evolved.  Its final state (not being wired for electricity, since it was in the far corner of my yard, originally) was a base that was a square galvanized ductwork with a hole in the center that I found in one of the bins at Home Depot with some dowels to support the drip cap.  (I eventually put a collar made out of some plastic pail or something around the legs to help hold them in place).  The drip cap was the bottom 1/2" or so of an appropriately sized Dollar Store plastic bucket with a hole in the bottom (more on that later.  On top of that was a plastic plate from Wal*Mart, upsidedown and also with a hole in the center, and caulked onto the top of that was the top part of a solar lamp from Lowe's that had the right shape.  For the actual glass, I got a lamp chimney from Vermont Lantern.  The one I got isn't in stock.  This looks to be the smallest one they have--and it looks pretty large if I'm reading this right: https://www.vermontlanterns.com/content/anchor-lamp-chimney-10  It isn't an actual lens like a true Fresnell, but it looks pretty good for $10.

Quote from: Volpone on Oct 06, 2018, 05:16 am
For the actual glass, I got a lamp chimney from Vermont Lantern. This looks to be the smallest one they have--and it looks pretty large if I'm reading this right: https://www.vermontlanterns.com/content/anchor-lamp-chimney-10

That lens you've linked to, Steve, is 3.5 inches in diameter and the same tall (Vermont Lanterns 3.5-inch ribbed chimney. (It's a globe, but Vermont refers to them as "chimneys".) It's for a lamp that's got a base of 5 inches in diameter and is 10 inches tall (10-inch Anchor Lamp). So the lens isn't very large at all.

Quote from: Volpone on Oct 06, 2018, 05:16 am
It isn't an actual lens like a true Fresnell, but it looks pretty good for $10.

Correct. This is one of those "ribbed" glass globes that simulates a Fresnel lens, but with the price of real Fresnels on the rise, the ribbed globe is one of those "close enoughs" that works, and for the price it can't be beat. Vermont also has other sizes of "chimneys" (Lamp Chimneys), and the most expensive ribbed one is 6 x 6 inches, and only $21.99 US. (The ribbed Fresnel versions are near the bottom of the page.)

Dino.

My actual lamp I used on my build was a inexpensive vapor outdoor light. I replaced the glass in it with a ribbed jelly jar for $3.  The drip cap is a ceiling fan cover where the light fixture normally goes.  My base is part of an indoor light that I cut to fit the base.  To fill gaps in everything I used a dense floor foam to weather proof it as best I could.  The little round ball is a pull chain handle that I through a screw through with some fender washers to hold it in the center, and hold the cap to the cage below.