Your mention of missing persons in the 1850's means I could guess that you suspect he was born in the 1840's or slightly earlier, but it is unclear.
As you don't mention the name we're unable to help with suggesting alternatives. For example, the Monair family I'm researching is often transcribed as McNair, and McNae is sometimes McRae. It's not just sound-alikes you should be looking for, but likely transcription errors.
Civil registration was not introduced in Scotland until 1855, after a long discussion. The birth (and baptism) records before are the "Old Parish Registers" which are on Scotlands People (pay site), and a subset are on Family Search.
Many registers did mention the birth date as well as baptism date, but the record keeping was quite informal compared to England. Here's an example from near Edinburgh in 1842:
However, the 1830's and 1840's were a time of turmoil for the church in Scotland leading to the Disruption of 1843. In short, over a third of the established church ministers broke away and formed a new free church. In many areas, this involved building new churches, and new administrative processes. During this time, it's quite likely many registers were poorly kept, or lost.
Any surviving registers had to be given to the General Register Office when civil registration started in 1855. This was unpopular so again more registers may have gone missing. Scotland's People has an article on the Old Parish Registers which mentions other reasons for missing registers and registrations, such as the cost.
In summary, only a proportion of births before 1855 were even recorded (varies by place and time), and only a proportion of those records still exist. The 1840's are an especially difficult period due to the changes at the churches, and the drift towards the large cities. So you may have to accept there is no record of the birth.
If you have his (English) marriage certificate, that should mention his father, and may give you clues as to where to look next.
Another approach if the name is at all rare: look at families with this name in Montrose and surrounding villages for 1841, 1851, 1861 (including families where the female head of household is unmarried). See if any had a son of roughly the right name and/or age who disappeared from later censuses (in Scotland), and maybe follow the families forward to see if any possible siblings also went to England. In other words, research each of the local families with that name and see where each person ends up.
Unless the name is very common you should be able to narrow it down to just a few families as it's a small town. Plus, check the names of his children to see if any were named after his possible father or mother or their parents, or have the possible mother's maiden name as a middle name.