I noticed that daij just treat the "v5aru" verbs as 動ラ五［四］. It made me wonder if we might want to make v5aru some kind of misc tag used in addition to v5r, instead of having it as its own verb class. There's of course nothing stopping the various dictionary implementations of JMDict to just list v5aru as v5r but treat them differently in conjugation tables, etc., but it seems like these verbs can still also be conjugated as regular v5r.
"おっしゃいます が現在では自然な使い方です。
ある特定の動詞に「ます」を付ける時、昔は「る」を「り」に変えて使っていましたが、時代を経て、「り」が「い」に変わりました。
なので、古い言い回しには「り」を使っているものがありますし、今でもあえて「り」を使っている人もいるようです。"
Another misc. tag we might want to implement is something for 良い and ない as they take on an extra "さ" when they get the suffix そう (first brought up by Chris Vasselli in the adj-i/adj-ix discussion).
Marcus