what you have there is a Sanwa-made panel.
Both Seimitsu and Sanwa made panels for Sega cabinets.
both also recently discontinued production.
since it’s a versus city, im gonna assume you’d want 1L6B (1 player centered) layout. As far as I know, Seimitsu only made "Astro City’ and “Blast City” themed 1L6B. if the design doesn’t bother you, then there you go, you can find used ones of them in various places, just post wanted listings and patience i guess, they are getting harder and harder to come by. Yahoo!Auctions Japan is a good source, but you’d have to go through proxy services.
there’s also these guys, try e-mailing them. http://www.rs2006.co.jp/j/arcade/conpane/ their panels are generic non sega-branded ones, but they allow for both sanwa and seimitsu to be mounted without any issues. kinda pricey though.
I THINK Jasen https://www.jasenscustoms.com/ is also offering arcade panels, ask him about it.
if you wanna mod the panels themselves, it should be straightforward, you’d just need to undo the weld, cut or snap off the mounting bracket. then jsut make necessary holes, using the LS-32 flat RS mounting plate as a guide. use carriage bolts (similar M4 size bolts with with smooth pan head used to secure the panel) to mount it, done. The LS-32’s are meant to be mounted a bit closer/flushed to the metal panel, so no need for spacers, i’d say.
hope this was helpful.