Would it be worth considering dropping in ND to balance the exposure time? Are you thinking of the side-of-the-head filter slot rather than the swing-away under the lens? Then there is the third option of using the rotating Separation Filter Wheel too. Rarely seen these days is a multiple flip-in filter holder that sits in place of the head-filter slot. Back when...it could be color printing, or poly-contrast filters with a tiny light for correct choice.
I use a Laborator 1000. So a quite different beast.
I had 2 options :
The first one was to buy the large set of filters and fit them in the filter holder between the lamphouse and the condenser set, keeping them in place with a thick glass plate cut to measures, which I do but find un practical, the other option was to buy a set of under the lesn filter, and a front ring from Cokin sized to my lenses front thread. On the Cokin adapter I put a Cokin Pro filter holder into which I slide the filter. It is a breeze to use, and to switch filters during a printing session.
You can also mount the under the lens Kodak holder to the arm supporting the red filter and use it to hold the filters.
Last but not least, the Agfa contrast filters are said to be useable above OR below the lens. If you find a new set, they are cheaper than the Kodak or Ilford under the lens kit....
You may want to ive a try.
I have purchased a set of Ilford 3 1/2" and sandwiching them in glass sounds good for use in the side drawer. I also received with the enlarger one of the multiple slide filter holders mentioned by "Clueless". These Ilfords appear to be the same size and I've thought about switching them with the originals as they look pretty crusty. It only holds 9 filters though. Thanks again.