So I can confirm aftermarket seats, without cutting frames or welding mounts to car, are completely possible.
If you have read my before method with the universal frames this way is a lot easier and more cost effective.
After 3 months of research I found a company called Planted Technology, they produced made to order seat sub frames for many cars. I emailed them to ensure my car was not an EK or an EG. I measured up the cars holes and got back the details of the closest fit frames they make.
The Honda Accord 4th & 5th gen have the same interior as the MB3/MB6.
I took a risk bought the frames and they do in fact directly fit.
I admit it was a bit of a fiddle as they had to come from America so may have been slightly warped or bent on delivery, never the less I got them in as seen in the image below
Here is a link to the main page, it would better off ordering them from GSM performance
Planted Technology https://www.plantedtechnology.com/products/planted-seat-bracket-honda-accord-4th-5th-generation-1989-1997-passenger-right
GSM performance https://www.sportseats4u.co.uk/product/planted-honda-accord-bracket/
Things to consider, these frames do not come with threads. M12 Nuts will be needed to fit seatbelts, M8 Nuts and bolts to fit seats to rails or frames, washers highly recommended