Some not necessarily expensive acoustic panels at primary wall reflection points to your main listening position may help. If so these would help similarly with the OHMs as well. With the OHMs, if you listen from more than one position, you might place panels at each primary reflection point for each location you listen from. I do this on side walls in my main listening room with one pair of Ohms and they do make a difference. In my other rooms I do not even bother and things are still fine if not quite so perfect. I may also try similar panels on ceiling primary reflection points some day but have not felt a great need to-date.
$55 for any properly operating OHm Walshes is a steal of the century! Lucky you! I’ve passed on some similar very good speaker deals at Goodwill because I have so many already but would not on that one! Also remember, last time I checked, any old OHMs with cabinets that can be refurbished and re-used have trade-in value with OHM. The condition of the drivers does not matter for trade-in. Last I checked (and took advantage of) OHM offered up to 40% off new speakers with trade in of two pair of older refurbishable OHMs. Need not be Walsh models even.
Lastly I would add that I’ve had OHM Walshes in my house since 1982 or so and A/B tested older versions versus new and the newer versions are more refined and detailed than the older ones, but the older versions are still great bargains for the prices commonly found.