I finally got around to building my smartHUB replacement:
BOM:
$ 0.00 weewx
$42.99 Raspberry Pi 3 starter kit with power supply
$ 9.99 32GB MicroSD card
$10.88 i2c-bus BMP280 barometer module (5 per lot, have 4 spares)
$ 5.49 180 degree USB adapter
$12.90 metal Pi2/3 case
$26.95 metal-cased SDR module
Total cost: $109.20
(If I wanted to go cheaper, I could have went with a plastic Pi case and a plastic SDR, and left the 180° adapter out.)
Acu-Rite's cost of a replacement smartHUB to replace my bricked unit - $79.99.
Still have some software tweaking to do, but everything is feeding into weewx and the barometer is working.....