”文“ ＝ 文化，包含禮樂及各項制度。
http://www.minlun.org.tw/3pt/3pt-2-5/3-14.htm

“範” 通 ”范“ ＝ 來自古書 ”洪範“, 是夏朝 （400 多年）政教設施之最高原則
http://web.thu.edu.tw/arche/www/PDF/hai.pdf

There is official classical Chinese record of 陳寔 when at his memorial service, the great general gave him the postumus name 諡 of 文範先生 to honour him as a respectable government official, who followed moral norms and governed with integrity.

“文 為德表，範 為士則”
See the quote and link below.

The Wikipedia link you provided matches the historical praise he received with regard to the famous reference of thief as 樑上君子 when he dealt with a burglary case, and the proverb 難兄難弟。

東漢時期誄、諡的實際操作情形，蔡邕〈陳太丘碑文〉即展示：

大將軍弔祠，錫以嘉諡，曰：「徵士陳君，稟嶽瀆之精，苞靈曜
之純。天不憖遺老，俾屏我王。梁崩哲萎，于時靡憲。搢紳儒林，
論德謀跡，諡曰文範先生。」《傳》曰：「郁郁乎文哉。」《書》
曰：「洪範九疇，彝倫攸敘。」文 為德表，範 為士則，存誨沒號，
不亦宜乎。三公遣令史祭以中牢。刺史敬弔。太守南陽曹府君命
官作誄曰：「赫矣陳君，命世是生。含光醇德，為士作程。資始
即正，守中又令。奉禮終沒，休矣清聲。」

See the text on page 10 of the link below:
http://ir.ndhu.edu.tw/bitstream/987654321/22563/2/05榮始而哀終：論漢...

Based on these findings, I suggest to translate 文範先生 as A gentleman with high morals and integrity.

Hope this helps.