Glad to see you're also reviving old skills - one thing the Pi has done for me.
PS. Surface mount is definitely the way to go - my biggest cost was in replacement drill bits - hence I only drilled the 6 Pi connections I needed.
I'll take your "decade" and multiply it by three - I got the Maplin "Double Strength" Ferric Chloride - through the post - when I was at college and I left there over 30 years ago. For this board I used Kicad, Injet on drafting film and a Maplin Bank Note Detector UV source. This was my first attempt at a i2c to 1 wire adapter - planning for dual - and it still works. A subsequent version, after I found I could go down to 0.3 mm, has been running for about 3 1/2 years now with 3 temperature sensors and 1 counter device.