[palegreenthumb]

Western Air Patrol (WAP) was the house brand of Western Auto Supply Co. of California (WASCoCA).  Their radios were manufactured mostly by Gilfillan in Los Angeles.  Some models are rebranded Pattersons, like the 11M3C and the 74AW, while many are rebranded Gilfillan models.  I can't say I've ever come across a WAP that was a rebranded Packard Bell, but at some point, the Packard Bell radios were also made by Gilfillan, so some similarity is not a surprise.  Many WAP radios have their model and serial numbers stamped in the metal chassis a la Gilfillan.

In 1939, George Pepperdine decided to sell WASCoCA to Gamble-Skogmo, in order to devote his attention to Pepperdine University.  The *least documented* WAP radio models I've encountered are the ones that went on the market in 1939.  They're identifiable by their linear dials and pushbuttons.  No schematics for them have ever been found.  It seems like, in the confusion of the Gambles merger, some details went missing.  They have several features that link them to Gilfillan products, suggesting they were still being made in L.A.

I've found a discussion of one WAP model released by Gambles in 1940; it was an untraceable battery radio.  After that, no info is available.  It seems Gambles eliminated the WAP brand of radios before the 1941 model year and continued only their own Coronado brand of radios (made largely by Wells-Gardner).

Don't trust the dates of WAP models in RadioMuseum.  Now that a few of them have been found, it seems the last digit of the model number is the best indicator of the year for the 4 years 1936-1939.  The 829, 929, and 1139 are all 1939 models, as far as I can tell.  Since WASCoCA was defunct thereafter, they can't be later than 1939.  A big bolus of WAP schematics was published in Riders in 1941 and 42, possibly released by Gilfillan after their deal with WASCoCA fell apart, but all of those radios are at least 5-6 years older than what's suggested by the publishing date of Riders.  So don't trust the dates in RadioMuseum.

I would guess the 388 model is an 8-tube model from 1938, like the 5-tube model 258 I have in my collection. Don't forget to count the eye tube. grillcloth.com shows it's likely to be a rebadged Gilfillan 8-APR:
http://www.grillecloth.com/sylvania/tube...ubmit&db=5

[Aside:  Truetone was the house brand of Western Auto Supply Co. (of Kansas City, KS).  Most of their radios came from midwest manufacturers, primarily Detrola.]