Any advice or ideas on what I should do?

Cutting the cabinets/countertops to put in a range will be way more work than finding a wall oven that fits.

If you go to appliance connection/aj Madison/ build.com etc you can filter pretty precisely on the dimensions you want.

What is the width of the cabinet underneath the cooktop? You might be able to fit a 30" or 27" wall oven underneath the cooktop. That would minimize the amount of cabinetry you have to alter.

Do you know the cutout width for the cooktop? A 30 or 36" slide-in induction range would be my choice. Bosch Industrial, Electrolux or Wolf are examples.

Built in place cabinets like that should be in the dumpster yesterday. They are incredibly dysfunctional compared to even builder grade modern cabinets.

you arent even showing the hood/ [or lack of].....pull back for a wider image. it may be this run could be pulled out and replaced w a range/hood/ and better drawer cabinets for the best long term benefit.

cant tell how many inches but RTA cabinets might be your solution. You could get a wood species or painted white mdf to match what you care to leave of the green on the other walls. 73 inches between right side of range top and to left side of oven cabinet ???? but how much more to this run?

I'll speak up in defence of old built-in-place cabinets. Our house had mostly 1958 original cabinets. Past owners had clearly done substantial modifications over the years--cabinets that had been altered had particle-board walls instead of plywood, lots of base rollouts had been added, and a complete reface sometime in the 80s. It was all still working great, with a few exceptions. Those cabinets could have easily kept working the same for another 20 years. And functionally, they weren't any different than putting in new standard cabinets.

New is nice when you can afford it and your needs call for it. But there are a lot of ways to keep the old going strong. And a lot of reasons sometimes. In OPs case, not trashing new countertops and tile.

Until you get this figured out here's my favorite air fryer/toaster oven. It'll do more then many new replacement ovens at $230. Amazon.com: Ninja DT201 Foodi 10-in-1 XL Pro Air Fry Digital Countertop Convection Toaster Oven with Dehydrate and Reheat, 1800 Watts, Stainless Steel Finish : Everything Else

I use this every day.

Here are more photos of the cabinets. It is a galley kitchen so if we update the cabinets on this side, the other side will have to be updated as well which then makes this an expensive project.

These photos were before the backsplash was added.

You could replace your cooktop with a new one and place a wall oven underneath. The old wall oven could be replaced the lost cabinet shelves under the current cooktop..

does not seem that charming or valuable. nice thing is the paint color would work w another finish but you can get "paint ready" mdf fronts. I would seriously get a good toaster oven and line item the inches there for project with with a range/ hood and base drawers.. in RTA.....those pesky things in the comment about "substantial modifications" and lingering " few exceptions"" ...add in higher labour to do something with the existing...I would be very nervous to spend and not get this good for another 20 years. You can do what you want obviously. .

your green is adaptable if you need to put in something else. ....

Classic Kitchen · More Info

full featured countertop appliance and 2nd ..SHARP USA model of mwave that attaches to the shelf at the top of your cubicle..maybe with reinforcement ...it vents from below so you can snug it in on the sides......there are very decent ways to get by for a time interval....

VEVOR Convection Oven Countertop Conventional Oven Electric Baking Oven, 20 L · More Info

1.5 Cu. Ft. 1100W Over the Counter Microwave, Black, Black · More Info

You've done a nice job updating your kitchen.

I would do the same layout and get the 24" oven (many of them are 24" nominally - or just at the front - so they FIT inside a 24" cabinet and the box is less. And of course pay close attention to the cutout required for a new cooktop.

Keep the existing appliances until you can replace it all. It's not worth what you're trying to do.

"The oven is 23” w x 30” l. Newer ovens are all 24” wide."

The tape measure shows 24".

But what are the model numbers of the oven and cooktop? Then we can find the cutout dimensions for the appliances and search for new appliances that would fit in the existing openings.

Wdccruise makes a good point about nominal opening sizes. Also, it looks like you have face frame cabinets. If so, you can probably trim the frame to fit most 24" ovens. If your oven has completely died, take it out and see what the raw opening looks like.

Personally, I would either install a range, or install a 30" wall oven under your cooktop. The old oven spot would look fantastic with shelves with a few serving items and/or cookbooks. But I also understand the benefit of simple solutions. If you are happy with another 24" oven, you can probably fit one there.