Looks to be withing charter for uk.rec.models.rail:
************Advertising Adverts should be clearly marked in the subject line (the words "AD", "For Sale", "Exhibition" or "Commercial" at the start of the subject line are recommended).
Short (less than 20 line) commercial announcements relevant to UK rail model making are permitted (either manufacturers or traders), though extensive advertising lists are not permitted (these should be available by mail, ftp or http to interested readers).
Commercial advertisers should not post adverts more frequently than once per month.
Private for-sale adverts are permitted, though should be short and concise. Discussion/negotiation should be via private email. Announcements by model railway clubs and societies are permitted, though should be concise and relevant. Announcement of model railway shows is permitted. Blatant off-topic or commercial advertising is not permitted.
************Tim