I kind of did this once, back in the early 90's I really really wanted a Defender boardset so I could play the game. This was in the time before the internet and forums so searching for what you wanted involved reading trade newspapers and phoning up all distributors asking for stuff, and Defender just never came up that much, as it was the time when machines and boards were just being skipped.
I found someone with a bootleg Defender called 'Defense Command' which I borrowed and started working on a 1:1 copy, I found out quite quickly that the RAM chips were going to be a problem to acquire as even back then the availability was limited.
So I decided to make a prototype first on copper strip board using 8K static ram chips rather than the 24x 4116 dynamic rams. Amazingly, it worked! I actually played my own bootleg of a bootleg, but this was only ever witnessed by my brother alas, and the prototype promptly died after a couple of months of kicking around my workbench. Probably a loose wire but the mess was so hard to fault find on, so I slung it on the scrap pile and robbed chips off it, which I always regret.
It played but it did have one issue, in making my own video circuit I had used the wrong clock speed for the pixel clock, so it turned out that all of the 48K ram was rendered on the screen, including the part where the CPU stores its program variables. So the display had this bar of random pixel noise down the right side of the screen, I think I bodged a circuit up to blank that off. It just meant that the picture was squished.
The plan then had been to hand route a pcb using the micro thin line tape and transfer prints of sockets onto clear acetate, but I only had a few print sets from an electronics supplier and I couldn't source any more so I gave up. PCB design software back in those days was mainly on DOS PCs and I had an Amiga 500, so I didn't have a chance really doing it digitally.
I use EagleCAD now and have designed a fair few boards with it, so it does the job for me.
So the only thing I'de point out with cloning a PacMan pcb is to remember the availability of what used to be common chips is no longer the case. I'm pretty sure the sprite line buffer ram chips (without me googling right now) are going to be pretty hard to come by, so any 1:1 copy with require chips off a source that will likely be another pacman board or clone. It'll be wiser to redesign it with new chips in mind, but that won't make it a 1:1 then.
