I've tried to match this layout as closely to the schematic for ease of reference. I added series protection (D6) instead of the factory parallel protection. IC's could be replaced with TL072, JRC4558 etc. Clipping diodes (D3, D4) could be replaced with 1N914, 1N4148. High, middle and low pot tapers were 'G' but I have noted them as linear taper. Try 2SK30, 2N5457 or similar for Q11. Try 2N3904, 2N5088 or similar for Q1, Q7, Q8 and Q10. Watch pinouts for the transistors. MidFreq pots are integrated in a dual-gang on the Boss pedal but you obviously don't have to do that, you'd be lucky to find a dual-gang 50K reverse taper pot anyhow. Sorry for all the standing resistors but it'll fit in a 125B solder-side up.
29/07/2018 UPDATE: I noticed a 100uf electro cap in the power section which needed orientation to be reversed so I fixed it and updated the layout with today's date. Link to the schematic: https://www.hobby-hour.com/electronics/s/boss-mt2-metal-zone.php