Hrm. I recommend at least the following too-
*Matthijs Vermeulen (Dutch, 7 symphonies, recorded on Donemus and some of them on Chandos)
*Niels-Viggo Bentzon (quite a few. Have heard two. Intriguing! Hrm. Not sure how many have been recorded. Seek out, I say.)
*Hilding Rosenberg. (a few on CD though not yet all 8, I -think-. Again though, seek out, worth hearing, good enjoyable worthwhile stuff.)
*Allan Pettersson (Swedish, 15? symphonies - 17 numbered but 2 of them may be incomplete??, so that's nos. 2 to 16 - but 2 to 16 are all recorded at least once. I have quite a few of them on CD etc. and am glad of it

)
*Mieczyslaw Weinberg (1919-1996. already mentioned in this thread. also sometimes called Moisei Vainberg, esp. on earlier recordings. Not all his symphonies recorded, but more and more are.)
*Vagn Holmboe (1909-1996. 13 symphonies, 3 chamber symphonies, 4 string symphonies. Almost all recorded (except maybe the 3 chamber symphonies, and I think that gap will probably be filled. Sometimes described as neoclassical, not really.)
*Hendrik Andriessen (father of Louis and Jurriaan, Louis has some greater fame

) - 4 symphonies
*Henk Badings (the label cpo is recording his symphonies. I have heard a few on the online archive of the radio station Concertzender. Pretty good.)
*Eduard Tubin (Estonian-Swedish. Somewhat better known, sort of.) 10 symphonies and an unfinished 11th. Very, very good indeed, or so I think; the brief 9th grabbed me as did some of the others when I first heard them 2 decades ago at my college music library; decided to get some of the CDs when I could (and there are now several recordings - indeed, two complete recordings of them, I think. To which I say yay!)
*Nikolay Myaskovsky - often Romantic in mind (though his symphonies 7 and 13 are- well, ok. Another pause here. "Romantic" and "19th-century-like" has to include music like late Liszt and Wagner for example (not only, emphatically) or else it would be good to define the term rather better. And as Schoenberg pointed out about a pupil's music (Berg's opus 3, I think, though unspecified), it doesn't go beyond the 19th century harmonically... he didn't say what music in the 19th century he was thinking of, but middle and late Liszt and Wagner is part of what I would guess. And others too. End{digression}.) Anyhow, Myaskovsky symphonies recommended by me, especially early but extremely passionate no.2 in C-sharp minor, but also the late war symphony no.22, and the slightly earlier no.20 (what a slow movement, and what becomes of it!), ... and others, too. And even more, though you didn't ask, some of the string quartets

I'm a fan of his. (Sorry

)
*Evgeny Golubev (1910-1981). Mostly only on LP at the movement (symphonies 5 and 7 out of, I think, 7); a few works on CD. Myaskovsky pupil; taught Schnittke. (I made MIDIs of some of his works and am convinced that I do need to hear more though. Quartets 8 and 9 are rather good.)
*Vissarion Shebalin (5 symphonies numbered, at least one unnumbered (haven't heard but has been recorded), all I think once available on Olympia CDs. Have heard the 5 numbered ones and recommend them, as I also do the 5 of Ukrainian Gliere pupil
*Borys Lyatoshynsky.
And seconding Havergal Brian and curious about Butting whose symphonies and 2 of whose quartets I have skimmed...