Herefords with poor markings?

I picked up some herefords on Saturday, had previously tried with them last year and failed miserably. I googled hereford genetics and this thread popped up (I should always look here first!).

The ones I picked up are a black trio. I have produced a few random brokens recently some of which have hereford facemarkings, others with rectangular belly marings and some with stops on the tail or white feet. None have all the appropriate hereford markings on the same mouse.

I want to just confrim a few things the hereford gene is known as w/n w/n meaning its a simple recessive gene? Infact it may not really be 'a gene' but a bundle of genes and modifyers?

Can I just bump this. Ive got loads more of these non-hereford hereford-looking mice.

I've done some test breeding with my 'proper' hereford buck to an unmarked doe, which has so far produced 12 babies, 11 of which had hereford markings and one self (not even white hairs!). So I have to assume because of the self that my hereford buck is a heterozygous hereford and that hereford is dominant.

I read on this thread that crossing herefords to other lines is bad for the variety which has resulted in them being small, mine are not that small but they dont have the type, particularly the glossy sheen to their coats that other dark show types do. The out crossed babies look great and healthy, the face markings are not broad enough however my hereford x hereford babies have resulted in some babies with really too wide face markings some going down onto the shoulder.