I picked up this interesting little Zenith Portable a couple of weeks ago. The L507 Meridian was basically the Poor man's H500 Transoceanic. BCB coverage along with 1-6MHZ and 6-18MHZ shortwave bands. No TO coil stack, and a standard rotary bandswitch.
http://i.imgur.com/S1keP3ul.jpg
After a Recap, restringing the dial cord, and building a battery pack for it, it plays great. The original Electrolytic can tested like new on all sections on my ESR tester, and the radio played with no AC hum after a recap, so it will stay for the time being.
http://i.imgur.com/iLGF6xHl.jpg
The 1L6 was weak, so I replaced it with one of the solid state replacements available on eBay. Also the power cord is twisted all to heck, but the insulation is still pliable, and since I tend to run my old portables almost exclusively on NIMH rechargeable batteries, It'll get replaced later.

Are you satisfied with the 1L6 replacement? I didn't know any were available. If this is a good fix for the 1L6 problem (rarity-cost), I would like to yank my few 1L6s that are working while they are working.

Nice looking radio! I wish all manufacturers had used the chassis material that Zenith used in this and the TO line. They almost always look brand new.

Reminds me of my recent acquisition, the Airline GSL1079 I recently posted. The shortwave range is the same 6-18 MHz as yours.

Ironically, today, this has an advantage. A 22m shortwave broadcast band (about 13,600-13,900 KHz) was added decades after these radios ended production. A vintage Trans-Oceanic can't tune that band, but your Meridian and my Airline will.

Are you satisfied with the 1L6 replacement? I didn't know any were available. If this is a good fix for the 1L6 problem (rarity-cost), I would like to yank my few 1L6s that are working while they are working.

Nice looking radio! I wish all manufacturers had used the chassis material that Zenith used in this and the TO line. They almost always look brand new.

The SS 1L6 replacement costs about $44 but absolutely blows away the performance of the real thing on the upper HF bands. Better selectivity and sensitivity all around. If you have A TO you really care about and use regularly on SW, buy one. It's worth it. Same seller also has IF amp "tubes" with built in ceramic filters.
I've had the Gen 1 Version in my (already beat to hell when I found it) daily use H500 since 2009 with no complaints. That Radio went with me to college, survived being dragged to bonfires in a creek bed in the woods on campus, drunks knocking it over, etc.
http://i.imgur.com/xMDyL1Nl.jpg
(pic taken during the Hurricane Sandy aftermath here in Ohio.)

Also, you're totally right about whatever Zenith used to plate these Chassis. It's freaking indestructible.