Here's some info on current value from the Blue Book of Gun Values:
WEBLEY NO. 4 PRYSE PATTERN
.32, .38, .44, .450, .455, .476, or .577 cal., double action, 3 to 5 3/4 in. barrel, numerous makers produced this model from the mid 1870s, Webley production covered a ser. no. range from 364 to 81,035.
Grading 100% 98% 95% 90% 80% 70% 60%
$2,500 $2,000 $1,500 $1,000 $800 $700 $600
Webley-marked models may command premiums over other makers. Cased, engraved, or inscribed examples will also command a premium.
Note that your serial number does not appear to fall in the Webley factory range. However, as you know, gun collectors love low serial numbers, consecutive serial numbers, and original boxes.
fyi,